Greek fire
Encyclopedia
Greek fire was an incendiary
weapon used by the Byzantine Empire
. The Byzantines typically used it in naval battles to great effect as it could continue burning while floating on water.
It provided a technological advantage, and was responsible for many key Byzantine military victories, most notably the salvation of Constantinople
from two Arab sieges, thus securing the Empire's survival.
The impression made by Greek fire on the European Crusaders
was such that the name was applied to any sort of incendiary weapon, including those used by Arab
s, the Chinese
, and the Mongols
. These, however, were different mixtures and not the Byzantine formula, which was a closely guarded state secret
, whose composition has now been lost. As a result, its ingredients are a much debated topic, with proposals including naphtha
, quicklime
, sulphur
, and niter
. What set the Byzantine usage of incendiary mixtures apart was their use of pressurized siphons to project the liquid onto the enemy.
Although the term "Greek fire" has been general in English and most other languages since the Crusades, in the original Byzantine sources it is called by a variety of names, such as "sea fire" , "Roman fire" , "war fire" , "liquid fire" , or "processed fire" .
- and bitumen-based mixtures. Incendiary arrows and pots containing combustible substances were used as early as the 9th century BC by the Assyrians, and were extensively used in the Greco-Roman world as well.
Furthermore, Thucydides
mentions the use of tubed flamethrower
s in the siege of Delium
in 424 BC. In naval warfare, the fleet of the Byzantine Emperor Anastasius I
(r. 491–518) is recorded by the chronicler John Malalas
as having utilized a sulphur-based mixture to defeat the revolt of Vitalian in AD 515, following the advice of a philosopher from Athens
called Proclus.
Greek fire proper, however, was invented in ca. 672, and is ascribed by the chronicler Theophanes
to Kallinikos, an architect from Heliopolis
in the former province of Phoenice, by then overrun by the Muslim conquests
. The historicity and exact chronology of this account is open to question: Theophanes reports the use of fire-carrying and siphon-equipped ships by the Byzantines a couple of years before the supposed arrival of Kallinikos at Constantinople. If this is not due to chronological confusion of the events of the siege, it may suggest that Kallinikos merely introduced an improved version of an established weapon. The historian James Partington
further thinks it likely that Greek fire was not in fact the discovery of any single person, but "invented by chemists in Constantinople who had inherited the discoveries of the Alexandria
n chemical school". Indeed, the 11th-century chronicler George Kedrenos records that Kallinikos came from Heliopolis
in Egypt
, but most scholars reject this as an error. Kedrenos also records the story, considered rather implausible, that Kallinikos' descendants, a family called "Lampros" ("Brilliant"), kept the secret of the fire's manufacture, and continued doing so to his day.
The invention of Greek fire came at a critical moment in the Byzantine Empire's history: weakened by its long wars with Sassanid Persia, the Byzantines had been unable to effectively resist the onslaught of the Muslim conquests
. Within a generation, Syria, Palestine and Egypt had fallen to the Arabs, who in ca. 672 set out to conquer the imperial capital of Constantinople
. The Greek fire was utilized to great effect against the Muslim fleets, helping to repel the Muslims at the first and second
Arab sieges of the city. Records of its use in later naval battles against the Saracens are more sporadic, but it did secure a number of victories, especially in the phase of Byzantine expansion in the late 9th and early 10th centuries. Utilisation of the substance was prominent in Byzantine civil wars, chiefly the revolt of the thematic fleets in 727 and the large-scale rebellion led by Thomas the Slav
in 821–823. In both cases, the rebel fleets were defeated by the Constantinopolitan Imperial Fleet through the use of Greek fire. The Byzantines also used the weapon to devastating effect against the various Rus' raids to the Bosporus
, especially those of 941 and 1043, as well as during the Bulgarian war of 970–971, when the fire-carrying Byzantine ships blockaded the Danube.
The importance placed on Greek fire during the Empire's struggle against the Arabs would lead to its discovery being ascribed to divine intervention. The Emperor Constantine Porphyrogennetos
(r. 945–959), in his book De Administrando Imperio
, admonishes his son and heir, Romanos II
(r. 959–963), to never reveal the secrets of its construction, as it was "shown and revealed by an angel to the great and holy first Christian emperor Constantine
" and that the angel bound him "not to prepare this fire but for Christians, and only in the imperial city". As a warning, he adds that one official, who was bribed into handing some of it over to the Empire's enemies, was struck down by a "flame from heaven" as he was about to enter a church. As the latter incident demonstrates, the Byzantines could not avoid capture of their precious secret weapon: the Arabs captured at least one fireship intact in 827, and the Bulgars captured several siphons and much of the substance itself in 812/814. This, however, was apparently not enough to allow their enemies to copy it (see below). The Arabs for instance employed a variety of incendiary substances similar to the Byzantine weapon, but they were never able to copy the Byzantine method of deployment by siphon, and used catapults and grenades instead.
Greek fire continued to be mentioned during the 12th century, and Anna Komnene
gives a vivid description of its use in a – possibly fictional – naval battle against the Pisa
ns in 1099. However, although the use of hastily improvised fireships is mentioned during the 1203 siege
of Constantinople by the Fourth Crusade
, no report confirms the use of the actual Greek fire, which had apparently fallen out of use, either because its secrets were forgotten, or because the Byzantines had lost access to the areas – the Caucasus
and the eastern coast of the Black Sea – where the primary ingredients were to be found.
s, the device used to prepare the substance by heating and pressurizing it, the siphon projecting it, and the special training of the siphōnarioi who used it. Knowledge of the whole system was highly compartmentalised, with operators and technicians aware of the secrets of only one component, ensuring that no enemy could gain knowledge of it in its entirety. This accounts for the fact that when the Bulgarians
took Mesembria
and Debeltos in 814, they captured 36 siphons and even quantities of the substance itself, but were unable to make any use of them.
The information available on Greek fire is exclusively indirect, based on references in the Byzantine military manuals
and a number of secondary historical sources such as Anna Komnene
and Western European chroniclers, which however are often inaccurate. In her Alexiad
, Anna Komnene provides a description of an incendiary weapon, which was used by the Byzantine garrison of Dyrrhachium in 1108 against the Normans
. It is often regarded as an at least partial "recipe" for Greek fire:
In attempting to reconstruct the Greek fire system, the concrete evidence, as it emerges from the contemporary literary references, provides the following characteristics:
, making it an early form of gunpowder
. This argument was based on the "thunder and smoke" description, as well as on the distance the flame could be projected from a siphon, which suggested an explosive discharge. From the times of Isaac Vossius
, several scholars adhered to this position, most notably the so-called "French school" during the 19th century, which included the famous chemist Marcellin Berthelot
. This view has been rejected since, as saltpeter does not appear to have been used in warfare in Europe or the Middle East before the 13th century, and is totally absent from the accounts of the Arabs, the foremost chemists of the Mediterranean world, before the same period. In addition, the nature of the proposed mixture would have been radically different from the siphon-projected substance described by Byzantine sources.
A second view, based on the fact that Greek fire was inextinguishable by water – rather, some sources suggest that pouring water on it intensified the flames – suggested that its destructive power was the result of the explosive reaction between water and quicklime. Although quicklime was certainly known and used by the Byzantines and the Arabs in warfare, the theory is refuted by literary and empirical evidence. A quicklime-based substance would have to come in contact with water to ignite, while Emperor Leo's Tactica
indicate that Greek fire was often poured directly on the decks of enemy ships, although admittedly, decks were kept wet due to lack of sealants. Likewise, Leo prescribes the use of grenades, which further reinforces the view that contact with water was not necessary for the substance's ignition. Furthermore, C. Zenghelis pointed out that, based on experiments, the actual result of the water-quicklime reaction would be negligible in the open sea. Another similar proposition suggested that Kallinikos had in fact discovered calcium phosphide
. On contact with water, calcium phosphide releases phosphine
, which ignites spontaneously. However, extensive experiments with it also failed to reproduce the described intensity of Greek fire.
Although the presence of either quicklime or saltpeter in the mixture cannot be entirely excluded, they were consequently not the primary ingredient. Most modern scholars agree that the actual Greek fire was based on petroleum
, either crude or refined; comparable to modern napalm
. The Byzantines had easy access to crude oil from the naturally occurring wells around the Black Sea
(e.g., the wells around Tmutorakan noted by Constantine Porphyrogennetos) or in various locations throughout the Middle East. An alternate name for Greek fire was "Median
fire" , and the 6th-century historian Procopius
, records that crude oil, which was called naphtha
(in Greek νάφθα, naphtha, from Middle Persian
نفت (naft)) by the Persians, was known to the Greeks as "Median oil" . This seems to corroborate the use of naphtha as a basic ingredient of Greek fire. There is also a surviving 9th-century Latin
text, preserved at Wolfenbüttel
in Germany, which mentions the ingredients of what appears to be Greek fire and the operation of the siphons used to project it. Although the text contains some inaccuracies, it clearly identifies the main component as naphtha. Resins were probably added as a thickener (the Praecepta Militaria
refer to the substance as , "sticky fire"), and to increase the duration and intensity of the flame.
A 12th-century treatise prepared by Mardi bin Ali al-Tarsusi
for Saladin
records an Arab version of Greek fire, called naft, which also had a petroleum base, with sulphur and various resins added. Any direct relation however with the Byzantine formula is very unlikely.
also mention that jars (kytrai or tzykalia) filled with Greek fire and caltrop
s wrapped with tow
and soaked in the substance were thrown by catapults, while pivoting crane
s (gerania) were employed to pour it upon enemy ships. The cheirosiphōnes especially were prescribed for use at land and in sieges, both against siege machines and against defenders on the walls, by several 10th-century military authors, and their use is depicted in the Poliorcetica
of Hero of Byzantium
.The Byzantine dromon
s usually had a siphōn installed on their prow under the forecastle, but additional devices could also on occasion be placed elsewhere on the ship. Thus in 941, when the Byzantines were facing the vastly more numerous Rus' fleet, siphons were placed also amidships and even astern.
s is amply attested in the contemporary sources. Anna Komnene gives this account of beast-shaped Greek fire projectors being mounted to the bow of warships:
Some sources provide more information on the composition and function of the whole mechanism. The Wolfenbüttel manuscript in particular provides the following description:
Another, possibly first-hand, account of the use of Greek fire comes from the 11th-century Yngvars saga víðförla
, where the Viking
Ingvar the Far-Travelled
faces ships equipped with Greek fire siphons:
The account, albeit embellished, corresponds with many of the characteristics of Greek fire known from other sources, such as a loud roar that accompanied its discharge. These two texts are also the only two sources that explicitly mention that the substance was heated over a furnace before being discharged; although the validity of this information is open to question, modern reconstructions have relied upon them.
Based on these descriptions and the Byzantine sources, John Haldon and Maurice Byrne reconstructed the entire apparatus as consisting of three main components: a bronze pump (the σίφων, siphōn proper), which was used to pressurize the oil; a brazier, used to heat the oil (πρόπυρον, propyron, "pre-heater"); and the nozzle, which was covered in bronze and mounted on a swivel (στρεπτόν, strepton). The brazier, burning a match of linen or flax that produced intense heat and the characteristic thick smoke, was used to heat oil and the other ingredients in an airtight tank above it, a process that also helped to dissolve the resins into a fluid mixture. The substance was pressurized by the heat and the usage of a force pump. After it had reached the proper pressure, a valve connecting the tank with the swivel was opened and the mixture was discharged from its end, being ignited at its mouth by some source of flame. The intense heat of the flame made necessary the presence of heat shields made of iron (βουκόλια, boukolia), which are attested in the fleet inventories.
The whole process was fraught with danger, as the mounting pressure could easily make the heated oil explode, although there are no recorded circumstances of such accidents. In the experiments conducted by Haldon in 2002 for the episode "Fireship" of the television series Machines Times Forgot, even modern welding techniques failed to secure adequate insulation of the bronze tank under pressure. This led to the relocation of the pressure pump between the tank and the nozzle. The full-scale device built on this basis established the effectiveness of the mechanism's design, even with the simple materials and techniques available to the Byzantines. The experiment used crude oil mixed with wood resins, and achieved a flame of over 1000 °C (1,832 °F) and an effective range of up to 15 metres (49.2 ft).
, is extensively attested in the military documents of the 10th century, and recommended for use in both sea and land. They first appear in the Tactica
of emperor Leo VI the Wise
, who claims to have invented them. Subsequent authors continued to refer to the cheirosiphōnes, especially for use against siege towers, although Nikephoros II Phokas also advises their use in field armies, with the aim of disrupting the enemy formation. Although both Leo VI and Nikephoros Phokas claim that the substance used in the cheirosiphōnes was the same as in the static devices used on ships, they were manifestly different devices than their larger cousins. This led Haldon and Byrne to theorize that the device was fundamentally different, "a simple syringe [that] squirted both liquid fire (presumably unignited) and noxious juices to repel enemy troops." Nevertheless, as the illustrations of Hero's Poliorcetica show, the hand-siphons too threw the ignited substance.
, most probably a seaborne variant of the Roman light catapult or onager
. These were capable of hurling light loads—around 6 to 9 kg (13.2 to 19.8 lb)—a distance of 350–450 m (382.8–492.1 yd). Later technological improvements in machining
technology enabled the devising of a pump mechanism discharging a stream of burning fluid (flame thrower) at close ranges, devastating wooden ships in naval warfare
. Such weapons were also very effective on land when used against besieging forces.
invincible. It was not, in the words of naval historian John Pryor, a "ship-killer" comparable to the naval ram
, which by then had fallen out of use. While Greek fire remained a potent weapon, its limitations were significant when compared to more traditional forms of artillery: in its siphon-deployed version, it had a limited range, and it could be used safely only in a calm sea and with favourable wind conditions. The enemy Muslim navies eventually adapted themselves to it, by staying out of its effective range and devising methods of protection such as felt or hides soaked in vinegar.
Incendiary device
Incendiary weapons, incendiary devices or incendiary bombs are bombs designed to start fires or destroy sensitive equipment using materials such as napalm, thermite, chlorine trifluoride, or white phosphorus....
weapon used by the Byzantine Empire
Byzantine Empire
The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...
. The Byzantines typically used it in naval battles to great effect as it could continue burning while floating on water.
It provided a technological advantage, and was responsible for many key Byzantine military victories, most notably the salvation of Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...
from two Arab sieges, thus securing the Empire's survival.
The impression made by Greek fire on the European Crusaders
Crusades
The Crusades were a series of religious wars, blessed by the Pope and the Catholic Church with the main goal of restoring Christian access to the holy places in and near Jerusalem...
was such that the name was applied to any sort of incendiary weapon, including those used by Arab
Arab
Arab people, also known as Arabs , are a panethnicity primarily living in the Arab world, which is located in Western Asia and North Africa. They are identified as such on one or more of genealogical, linguistic, or cultural grounds, with tribal affiliations, and intra-tribal relationships playing...
s, the Chinese
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, and the Mongols
Mongols
Mongols ) are a Central-East Asian ethnic group that lives mainly in the countries of Mongolia, China, and Russia. In China, ethnic Mongols can be found mainly in the central north region of China such as Inner Mongolia...
. These, however, were different mixtures and not the Byzantine formula, which was a closely guarded state secret
Classified information
Classified information is sensitive information to which access is restricted by law or regulation to particular groups of persons. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation...
, whose composition has now been lost. As a result, its ingredients are a much debated topic, with proposals including naphtha
Naphtha
Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons, i.e., a component of natural gas condensate or a distillation product from petroleum, coal tar or peat boiling in a certain range and containing certain hydrocarbons. It is a broad term covering among the...
, quicklime
Calcium oxide
Calcium oxide , commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline crystalline solid at room temperature....
, sulphur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
, and niter
Niter
Niter or nitre is the mineral form of potassium nitrate, KNO3, also known as saltpeter or saltpetre . Historically, the term "niter" – cognate with "natrium", a Latin word for sodium – has been very vaguely defined, and it has been applied to a variety of other minerals and chemical compounds,...
. What set the Byzantine usage of incendiary mixtures apart was their use of pressurized siphons to project the liquid onto the enemy.
Although the term "Greek fire" has been general in English and most other languages since the Crusades, in the original Byzantine sources it is called by a variety of names, such as "sea fire" , "Roman fire" , "war fire" , "liquid fire" , or "processed fire" .
History
Incendiary and flaming weapons were used in warfare for centuries prior to the invention of Greek fire. They included a number of sulphur-, petroleumPetroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
- and bitumen-based mixtures. Incendiary arrows and pots containing combustible substances were used as early as the 9th century BC by the Assyrians, and were extensively used in the Greco-Roman world as well.
Furthermore, Thucydides
Thucydides
Thucydides was a Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th century BC war between Sparta and Athens to the year 411 BC...
mentions the use of tubed flamethrower
Flamethrower
A flamethrower is a mechanical device designed to project a long controllable stream of fire.Some flamethrowers project a stream of ignited flammable liquid; some project a long gas flame. Most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and...
s in the siege of Delium
Battle of Delium
The Battle of Delium or of Delion took place in 424 BC between the Athenians and the Boeotians, and ended with the siege of Delium in the following weeks.-Prelude:...
in 424 BC. In naval warfare, the fleet of the Byzantine Emperor Anastasius I
Anastasius I (emperor)
Anastasius I was Byzantine Emperor from 491 to 518. During his reign the Roman eastern frontier underwent extensive re-fortification, including the construction of Dara, a stronghold intended to counter the Persian fortress of Nisibis....
(r. 491–518) is recorded by the chronicler John Malalas
John Malalas
John Malalas or Ioannes Malalas was a Greek chronicler from Antioch. Malalas is probably a Syriac word for "rhetor", "orator"; it is first applied to him by John of Damascus .-Life:Malalas was educated in Antioch, and probably was a jurist there, but moved to...
as having utilized a sulphur-based mixture to defeat the revolt of Vitalian in AD 515, following the advice of a philosopher from Athens
Athens
Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...
called Proclus.
Greek fire proper, however, was invented in ca. 672, and is ascribed by the chronicler Theophanes
Theophanes the Confessor
Saint Theophanes Confessor was a member of the Byzantine aristocracy, who became a monk and chronicler. He is venerated on March 12 in the Roman Catholic and the Eastern Orthodox Church .-Biography:Theophanes was born in Constantinople of wealthy and noble iconodule parents: Isaac,...
to Kallinikos, an architect from Heliopolis
Baalbek
Baalbek is a town in the Beqaa Valley of Lebanon, altitude , situated east of the Litani River. It is famous for its exquisitely detailed yet monumentally scaled temple ruins of the Roman period, when Baalbek, then known as Heliopolis, was one of the largest sanctuaries in the Empire...
in the former province of Phoenice, by then overrun by the Muslim conquests
Muslim conquests
Muslim conquests also referred to as the Islamic conquests or Arab conquests, began with the Islamic prophet Muhammad. He established a new unified polity in the Arabian Peninsula which under the subsequent Rashidun and Umayyad Caliphates saw a century of rapid expansion of Muslim power.They...
. The historicity and exact chronology of this account is open to question: Theophanes reports the use of fire-carrying and siphon-equipped ships by the Byzantines a couple of years before the supposed arrival of Kallinikos at Constantinople. If this is not due to chronological confusion of the events of the siege, it may suggest that Kallinikos merely introduced an improved version of an established weapon. The historian James Partington
J. R. Partington
James Riddick Partington MBE was a British chemist and historian of chemistry.- Life and work :Partington was born in Bolton, Lancashire and was educated at the University of Manchester, where he obtained First Class Honours...
further thinks it likely that Greek fire was not in fact the discovery of any single person, but "invented by chemists in Constantinople who had inherited the discoveries of the Alexandria
Alexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...
n chemical school". Indeed, the 11th-century chronicler George Kedrenos records that Kallinikos came from Heliopolis
Heliopolis (ancient)
Heliopolis was one of the oldest cities of ancient Egypt, the capital of the 13th Lower Egyptian nome that was located five miles east of the Nile to the north of the apex of the Nile Delta...
in Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
, but most scholars reject this as an error. Kedrenos also records the story, considered rather implausible, that Kallinikos' descendants, a family called "Lampros" ("Brilliant"), kept the secret of the fire's manufacture, and continued doing so to his day.
The invention of Greek fire came at a critical moment in the Byzantine Empire's history: weakened by its long wars with Sassanid Persia, the Byzantines had been unable to effectively resist the onslaught of the Muslim conquests
Muslim conquests
Muslim conquests also referred to as the Islamic conquests or Arab conquests, began with the Islamic prophet Muhammad. He established a new unified polity in the Arabian Peninsula which under the subsequent Rashidun and Umayyad Caliphates saw a century of rapid expansion of Muslim power.They...
. Within a generation, Syria, Palestine and Egypt had fallen to the Arabs, who in ca. 672 set out to conquer the imperial capital of Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...
. The Greek fire was utilized to great effect against the Muslim fleets, helping to repel the Muslims at the first and second
Siege of Constantinople (718)
The Second Arab Siege of Constantinople was a combined land and sea effort by the Arabs to take the capital city of the Byzantine Empire, Constantinople. The Arab ground forces, led by Maslamah ibn Abd al-Malik, were held off by the massive city walls, decimated by an outbreak of plague and...
Arab sieges of the city. Records of its use in later naval battles against the Saracens are more sporadic, but it did secure a number of victories, especially in the phase of Byzantine expansion in the late 9th and early 10th centuries. Utilisation of the substance was prominent in Byzantine civil wars, chiefly the revolt of the thematic fleets in 727 and the large-scale rebellion led by Thomas the Slav
Thomas the Slav
Thomas the Slav was a 9th-century Byzantine military commander, most notable for leading a wide-scale revolt against Emperor Michael II the Amorian in 820–823....
in 821–823. In both cases, the rebel fleets were defeated by the Constantinopolitan Imperial Fleet through the use of Greek fire. The Byzantines also used the weapon to devastating effect against the various Rus' raids to the Bosporus
Bosporus
The Bosphorus or Bosporus , also known as the Istanbul Strait , is a strait that forms part of the boundary between Europe and Asia. It is one of the Turkish Straits, along with the Dardanelles...
, especially those of 941 and 1043, as well as during the Bulgarian war of 970–971, when the fire-carrying Byzantine ships blockaded the Danube.
The importance placed on Greek fire during the Empire's struggle against the Arabs would lead to its discovery being ascribed to divine intervention. The Emperor Constantine Porphyrogennetos
Constantine VII
Constantine VII Porphyrogennetos or Porphyrogenitus, "the Purple-born" was the fourth Emperor of the Macedonian dynasty of the Byzantine Empire, reigning from 913 to 959...
(r. 945–959), in his book De Administrando Imperio
De Administrando Imperio
De Administrando Imperio is the Latin title of a Greek work written by the 10th-century Eastern Roman Emperor Constantine VII. The Greek title of the work is...
, admonishes his son and heir, Romanos II
Romanos II
Romanos II was a Byzantine emperor. He succeeded his father Constantine VII in 959 at the age of twenty-one, and died suddenly in 963.-Life:...
(r. 959–963), to never reveal the secrets of its construction, as it was "shown and revealed by an angel to the great and holy first Christian emperor Constantine
Constantine I
Constantine the Great , also known as Constantine I or Saint Constantine, was Roman Emperor from 306 to 337. Well known for being the first Roman emperor to convert to Christianity, Constantine and co-Emperor Licinius issued the Edict of Milan in 313, which proclaimed religious tolerance of all...
" and that the angel bound him "not to prepare this fire but for Christians, and only in the imperial city". As a warning, he adds that one official, who was bribed into handing some of it over to the Empire's enemies, was struck down by a "flame from heaven" as he was about to enter a church. As the latter incident demonstrates, the Byzantines could not avoid capture of their precious secret weapon: the Arabs captured at least one fireship intact in 827, and the Bulgars captured several siphons and much of the substance itself in 812/814. This, however, was apparently not enough to allow their enemies to copy it (see below). The Arabs for instance employed a variety of incendiary substances similar to the Byzantine weapon, but they were never able to copy the Byzantine method of deployment by siphon, and used catapults and grenades instead.
Greek fire continued to be mentioned during the 12th century, and Anna Komnene
Anna Komnene
Anna Komnene, Latinized as Comnena was a Greek princess and scholar and the daughter of Emperor Alexios I Komnenos of Byzantium and Irene Doukaina...
gives a vivid description of its use in a – possibly fictional – naval battle against the Pisa
Pisa
Pisa is a city in Tuscany, Central Italy, on the right bank of the mouth of the River Arno on the Tyrrhenian Sea. It is the capital city of the Province of Pisa...
ns in 1099. However, although the use of hastily improvised fireships is mentioned during the 1203 siege
Siege of Constantinople (1203)
The Siege of Constantinople in 1203 was a Crusader siege of the capital of the Byzantine Empire, in support of the deposed emperor Isaac II Angelos and his son Alexios IV Angelos.- The siege :...
of Constantinople by the Fourth Crusade
Fourth Crusade
The Fourth Crusade was originally intended to conquer Muslim-controlled Jerusalem by means of an invasion through Egypt. Instead, in April 1204, the Crusaders of Western Europe invaded and conquered the Christian city of Constantinople, capital of the Eastern Roman Empire...
, no report confirms the use of the actual Greek fire, which had apparently fallen out of use, either because its secrets were forgotten, or because the Byzantines had lost access to the areas – the Caucasus
Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...
and the eastern coast of the Black Sea – where the primary ingredients were to be found.
General characteristics
As Constantine Porphyrogennetos' warnings show, the ingredients and the processes of manufacture and deployment of Greek fire were extremely carefully guarded military secrets. So strict was the secrecy that the composition of Greek fire was lost forever and remains a source of speculation to this day. Consequently, the "mystery" of the formula has long dominated the research into Greek fire. Despite this almost exclusive focus, however, Greek fire is best understood as a complete weapon system of many components, all of which were needed to operate together to render it effective. This comprised not only the formula of its composition, but also the specialized dromonDromon
The dromon was a type of galley and the most important warship of the Byzantine navy from the 6th to 12th centuries AD...
s, the device used to prepare the substance by heating and pressurizing it, the siphon projecting it, and the special training of the siphōnarioi who used it. Knowledge of the whole system was highly compartmentalised, with operators and technicians aware of the secrets of only one component, ensuring that no enemy could gain knowledge of it in its entirety. This accounts for the fact that when the Bulgarians
First Bulgarian Empire
The First Bulgarian Empire was a medieval Bulgarian state founded in the north-eastern Balkans in c. 680 by the Bulgars, uniting with seven South Slavic tribes...
took Mesembria
Nesebar
Nesebar is an ancient town and one of the major seaside resorts on the Bulgarian Black Sea Coast, located in Burgas Province. It is the administrative centre of the homonymous Nesebar Municipality...
and Debeltos in 814, they captured 36 siphons and even quantities of the substance itself, but were unable to make any use of them.
The information available on Greek fire is exclusively indirect, based on references in the Byzantine military manuals
Byzantine military manuals
This article lists and briefly discusses the most important of a large number of treatises on military science produced in the Byzantine Empire.- Background :...
and a number of secondary historical sources such as Anna Komnene
Anna Komnene
Anna Komnene, Latinized as Comnena was a Greek princess and scholar and the daughter of Emperor Alexios I Komnenos of Byzantium and Irene Doukaina...
and Western European chroniclers, which however are often inaccurate. In her Alexiad
Alexiad
The Alexiad is a medieval biographical text written around the year 1148 by the Byzantine historian Anna Comnena, daughter of Emperor Alexius I....
, Anna Komnene provides a description of an incendiary weapon, which was used by the Byzantine garrison of Dyrrhachium in 1108 against the Normans
Normans
The Normans were the people who gave their name to Normandy, a region in northern France. They were descended from Norse Viking conquerors of the territory and the native population of Frankish and Gallo-Roman stock...
. It is often regarded as an at least partial "recipe" for Greek fire:
"This fire is made by the following arts. From the pine and the certain such evergreen trees inflammable resin is collected. This is rubbed with sulphur and put into tubes of reed, and is blown by men using it with violent and continuous breath. Then in this manner it meets the fire on the tip and catches light and falls like a fiery whirlwind on the faces of the enemies."At the same time, the reports by Western chroniclers of the famed ignis graecus are largely unreliable, since they apply the name to any and all sorts of incendiary substances.
In attempting to reconstruct the Greek fire system, the concrete evidence, as it emerges from the contemporary literary references, provides the following characteristics:
- It burned on water, and, according to some interpretations, was ignited by water. In addition, as numerous writers testify, it could be extinguished only by a few substances, such as sand (which deprived it of oxygen), strong vinegar, or old urine, presumably by some sort of chemical reaction.
- It was a liquid substance, and not some sort of projectile, as verified both by descriptions and the very name "liquid fire".
- At sea, it was usually ejected from siphons, although earthenware pots or grenades filled with it or similar substances were also used.
- The discharge of Greek fire was accompanied by "thunder" and "much smoke".
Theories on composition
The first and, for a long time, most popular theory regarding the composition of Greek fire held that its chief ingredient was saltpeterPotassium nitrate
Potassium nitrate is a chemical compound with the formula KNO3. It is an ionic salt of potassium ions K+ and nitrate ions NO3−.It occurs as a mineral niter and is a natural solid source of nitrogen. Its common names include saltpetre , from medieval Latin sal petræ: "stone salt" or possibly "Salt...
, making it an early form of gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
. This argument was based on the "thunder and smoke" description, as well as on the distance the flame could be projected from a siphon, which suggested an explosive discharge. From the times of Isaac Vossius
Isaac Vossius
Isaak Vossius, sometimes anglicised Isaac Voss was a Dutch scholar and manuscript collector.-Life:...
, several scholars adhered to this position, most notably the so-called "French school" during the 19th century, which included the famous chemist Marcellin Berthelot
Marcellin Berthelot
Marcelin Pierre Eugène Berthelot was a French chemist and politician noted for the Thomsen-Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances and disproved the theory of vitalism. He is considered as one of the greatest chemists of all time.He...
. This view has been rejected since, as saltpeter does not appear to have been used in warfare in Europe or the Middle East before the 13th century, and is totally absent from the accounts of the Arabs, the foremost chemists of the Mediterranean world, before the same period. In addition, the nature of the proposed mixture would have been radically different from the siphon-projected substance described by Byzantine sources.
A second view, based on the fact that Greek fire was inextinguishable by water – rather, some sources suggest that pouring water on it intensified the flames – suggested that its destructive power was the result of the explosive reaction between water and quicklime. Although quicklime was certainly known and used by the Byzantines and the Arabs in warfare, the theory is refuted by literary and empirical evidence. A quicklime-based substance would have to come in contact with water to ignite, while Emperor Leo's Tactica
Tactica of Emperor Leo VI the Wise
The Tactica is a military treatise written by or on behalf of Byzantine Emperor Leo VI the Wise in ca. 895-908. Drawing on earlier authors such as Aelian, Onasander and the Strategikon of emperor Maurice, it is one of the major works on Byzantine military tactics, written on the eve of Byzantium's...
indicate that Greek fire was often poured directly on the decks of enemy ships, although admittedly, decks were kept wet due to lack of sealants. Likewise, Leo prescribes the use of grenades, which further reinforces the view that contact with water was not necessary for the substance's ignition. Furthermore, C. Zenghelis pointed out that, based on experiments, the actual result of the water-quicklime reaction would be negligible in the open sea. Another similar proposition suggested that Kallinikos had in fact discovered calcium phosphide
Calcium phosphide
Calcium phosphide is a chemical is used in incendiary bombs. It has the appearance of red-brown crystalline powder or grey lumps, with melting point of 1600 °C. Its trade name is Photophor for the incendiary use or Polythanol for the use as rodenticide.It may be formed by reaction of the elements...
. On contact with water, calcium phosphide releases phosphine
Phosphine
Phosphine is the compound with the chemical formula PH3. It is a colorless, flammable, toxic gas. Pure phosphine is odourless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphine...
, which ignites spontaneously. However, extensive experiments with it also failed to reproduce the described intensity of Greek fire.
Although the presence of either quicklime or saltpeter in the mixture cannot be entirely excluded, they were consequently not the primary ingredient. Most modern scholars agree that the actual Greek fire was based on petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
, either crude or refined; comparable to modern napalm
Napalm
Napalm is a thickening/gelling agent generally mixed with gasoline or a similar fuel for use in an incendiary device, primarily as an anti-personnel weapon...
. The Byzantines had easy access to crude oil from the naturally occurring wells around the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
(e.g., the wells around Tmutorakan noted by Constantine Porphyrogennetos) or in various locations throughout the Middle East. An alternate name for Greek fire was "Median
Medes
The MedesThe Medes...
fire" , and the 6th-century historian Procopius
Procopius
Procopius of Caesarea was a prominent Byzantine scholar from Palestine. Accompanying the general Belisarius in the wars of the Emperor Justinian I, he became the principal historian of the 6th century, writing the Wars of Justinian, the Buildings of Justinian and the celebrated Secret History...
, records that crude oil, which was called naphtha
Naphtha
Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons, i.e., a component of natural gas condensate or a distillation product from petroleum, coal tar or peat boiling in a certain range and containing certain hydrocarbons. It is a broad term covering among the...
(in Greek νάφθα, naphtha, from Middle Persian
Middle Persian
Middle Persian , indigenously known as "Pârsig" sometimes referred to as Pahlavi or Pehlevi, is the Middle Iranian language/ethnolect of Southwestern Iran that during Sassanid times became a prestige dialect and so came to be spoken in other regions as well. Middle Persian is classified as a...
نفت (naft)) by the Persians, was known to the Greeks as "Median oil" . This seems to corroborate the use of naphtha as a basic ingredient of Greek fire. There is also a surviving 9th-century Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
text, preserved at Wolfenbüttel
Wolfenbüttel
Wolfenbüttel is a town in Lower Saxony, Germany, located on the Oker river about 13 kilometres south of Brunswick. It is the seat of the District of Wolfenbüttel and of the bishop of the Protestant Lutheran State Church of Brunswick...
in Germany, which mentions the ingredients of what appears to be Greek fire and the operation of the siphons used to project it. Although the text contains some inaccuracies, it clearly identifies the main component as naphtha. Resins were probably added as a thickener (the Praecepta Militaria
Praecepta Militaria
The Praecepta Militaria is the Latin conventional title given to a Byzantine military treatise, written in ca. 965 by or on behalf of Byzantine Emperor Nikephoros Phokas...
refer to the substance as , "sticky fire"), and to increase the duration and intensity of the flame.
A 12th-century treatise prepared by Mardi bin Ali al-Tarsusi
Mardi bin Ali al-Tarsusi
Mardi bin Ali al-Tarsusi was a 12th century Ayyubid writer and expert on military matters. He wrote a number of treatises, including a military manual for Saladin in 1187...
for Saladin
Saladin
Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb , better known in the Western world as Saladin, was an Arabized Kurdish Muslim, who became the first Sultan of Egypt and Syria, and founded the Ayyubid dynasty. He led Muslim and Arab opposition to the Franks and other European Crusaders in the Levant...
records an Arab version of Greek fire, called naft, which also had a petroleum base, with sulphur and various resins added. Any direct relation however with the Byzantine formula is very unlikely.
Methods of deployment
The chief method of deployment of Greek fire, which sets it apart from similar substances, was its projection through a tube (siphōn), for use aboard ships or in sieges. Portable projectors (cheirosiphōnes) were also invented, reputedly by Emperor Leo VI. The Byzantine military manualsByzantine military manuals
This article lists and briefly discusses the most important of a large number of treatises on military science produced in the Byzantine Empire.- Background :...
also mention that jars (kytrai or tzykalia) filled with Greek fire and caltrop
Caltrop
A caltrop is an antipersonnel weapon made up of two or more sharp nails or spines arranged in such a manner that one of them always points upward from a stable base...
s wrapped with tow
Tow
In the composites industry, a tow is an untwisted bundle of continuous filaments, and it refers to man-made fibres, particularly carbon fibres ....
and soaked in the substance were thrown by catapults, while pivoting crane
Crane (machine)
A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...
s (gerania) were employed to pour it upon enemy ships. The cheirosiphōnes especially were prescribed for use at land and in sieges, both against siege machines and against defenders on the walls, by several 10th-century military authors, and their use is depicted in the Poliorcetica
Poliorcetica
A poliorceticon is any member of the genre of Byzantine literature dealing with manuals on siege warfare, which is formally known as poliorcetics. As with much Byzantine literature, the poliorcetica tend to be compendia of earlier guides illustrated with Biblical and Classical anecdotes...
of Hero of Byzantium
Hero of Byzantium
Hero of Byzantium is believed to be the literary pseudonym of an otherwise anonymous Byzantine author of a poliorketikon, an illustrated manual of siegecraft, dating from circa 950. He is also credited with the Geodaesia, a work in practical geometry and ballistics which makes use of locations...
.The Byzantine dromon
Dromon
The dromon was a type of galley and the most important warship of the Byzantine navy from the 6th to 12th centuries AD...
s usually had a siphōn installed on their prow under the forecastle, but additional devices could also on occasion be placed elsewhere on the ship. Thus in 941, when the Byzantines were facing the vastly more numerous Rus' fleet, siphons were placed also amidships and even astern.
Siphon projectors
The use of siphonSiphon
The word siphon is sometimes used to refer to a wide variety of devices that involve the flow of liquids through tubes. But in the English language today, the word siphon usually refers to a tube in an inverted U shape which causes a liquid to flow uphill, above the surface of the reservoir,...
s is amply attested in the contemporary sources. Anna Komnene gives this account of beast-shaped Greek fire projectors being mounted to the bow of warships:
"As he [the Emperor Alexios I] knew that the PisaPisaPisa is a city in Tuscany, Central Italy, on the right bank of the mouth of the River Arno on the Tyrrhenian Sea. It is the capital city of the Province of Pisa...
ns were skilled in sea warfare and dreaded a battle with them, on the prow of each ship he had a head fixed of a lion or other land-animal, made in brass or iron with the mouth open and then gilded over, so that their mere aspect was terrifying. And the fire which was to be directed against the enemy through tubes he made to pass through the mouths of the beasts, so that it seemed as if the lions and the other similar monsters were vomiting the fire."
Some sources provide more information on the composition and function of the whole mechanism. The Wolfenbüttel manuscript in particular provides the following description:
"...having built a furnace right at the front of the ship, they set on it a copper vessel full of these things, having put fire underneath. And one of them, having made a bronze tube similar to that which the rustics call a squitiatoria, "squirt", with which boys play, they spray [it] at the enemy."
Another, possibly first-hand, account of the use of Greek fire comes from the 11th-century Yngvars saga víðförla
Yngvars saga víðförla
Yngvars saga víðförla is a legendary saga said to have been written in the twelfth century by Oddr Snorrason. Scholars have been skeptical towards this claim but in recent years it has gained more acceptance....
, where the Viking
Viking
The term Viking is customarily used to refer to the Norse explorers, warriors, merchants, and pirates who raided, traded, explored and settled in wide areas of Europe, Asia and the North Atlantic islands from the late 8th to the mid-11th century.These Norsemen used their famed longships to...
Ingvar the Far-Travelled
Ingvar the Far-Travelled
Ingvar the Far-Travelled was the leader of an unsuccessful Viking attack against Persia, in 1036–1042.There were several Caspian expeditions of the Rus' in the course of the 10th century...
faces ships equipped with Greek fire siphons:
"[They] began blowing with smiths’ bellows at a furnace in which there was fire and there came from it a great din. There stood there also a brass [or bronze] tube and from it flew much fire against one ship, and it burned up in a short time so that all of it became white ashes..."
The account, albeit embellished, corresponds with many of the characteristics of Greek fire known from other sources, such as a loud roar that accompanied its discharge. These two texts are also the only two sources that explicitly mention that the substance was heated over a furnace before being discharged; although the validity of this information is open to question, modern reconstructions have relied upon them.
Based on these descriptions and the Byzantine sources, John Haldon and Maurice Byrne reconstructed the entire apparatus as consisting of three main components: a bronze pump (the σίφων, siphōn proper), which was used to pressurize the oil; a brazier, used to heat the oil (πρόπυρον, propyron, "pre-heater"); and the nozzle, which was covered in bronze and mounted on a swivel (στρεπτόν, strepton). The brazier, burning a match of linen or flax that produced intense heat and the characteristic thick smoke, was used to heat oil and the other ingredients in an airtight tank above it, a process that also helped to dissolve the resins into a fluid mixture. The substance was pressurized by the heat and the usage of a force pump. After it had reached the proper pressure, a valve connecting the tank with the swivel was opened and the mixture was discharged from its end, being ignited at its mouth by some source of flame. The intense heat of the flame made necessary the presence of heat shields made of iron (βουκόλια, boukolia), which are attested in the fleet inventories.
The whole process was fraught with danger, as the mounting pressure could easily make the heated oil explode, although there are no recorded circumstances of such accidents. In the experiments conducted by Haldon in 2002 for the episode "Fireship" of the television series Machines Times Forgot, even modern welding techniques failed to secure adequate insulation of the bronze tank under pressure. This led to the relocation of the pressure pump between the tank and the nozzle. The full-scale device built on this basis established the effectiveness of the mechanism's design, even with the simple materials and techniques available to the Byzantines. The experiment used crude oil mixed with wood resins, and achieved a flame of over 1000 °C (1,832 °F) and an effective range of up to 15 metres (49.2 ft).
Hand-held siphons
The portable cheirosiphōn ("hand-siphon"), the earliest analogue to a modern flamethrowerFlamethrower
A flamethrower is a mechanical device designed to project a long controllable stream of fire.Some flamethrowers project a stream of ignited flammable liquid; some project a long gas flame. Most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and...
, is extensively attested in the military documents of the 10th century, and recommended for use in both sea and land. They first appear in the Tactica
Tactica of Emperor Leo VI the Wise
The Tactica is a military treatise written by or on behalf of Byzantine Emperor Leo VI the Wise in ca. 895-908. Drawing on earlier authors such as Aelian, Onasander and the Strategikon of emperor Maurice, it is one of the major works on Byzantine military tactics, written on the eve of Byzantium's...
of emperor Leo VI the Wise
Leo VI the Wise
Leo VI, surnamed the Wise or the Philosopher , was Byzantine emperor from 886 to 912. The second ruler of the Macedonian dynasty , he was very well-read, leading to his surname...
, who claims to have invented them. Subsequent authors continued to refer to the cheirosiphōnes, especially for use against siege towers, although Nikephoros II Phokas also advises their use in field armies, with the aim of disrupting the enemy formation. Although both Leo VI and Nikephoros Phokas claim that the substance used in the cheirosiphōnes was the same as in the static devices used on ships, they were manifestly different devices than their larger cousins. This led Haldon and Byrne to theorize that the device was fundamentally different, "a simple syringe [that] squirted both liquid fire (presumably unignited) and noxious juices to repel enemy troops." Nevertheless, as the illustrations of Hero's Poliorcetica show, the hand-siphons too threw the ignited substance.
Grenades
In its earliest form, Greek fire was hurled onto enemy forces by firing a burning cloth-wrapped ball, perhaps containing a flask, using a form of light catapultCatapult
A catapult is a device used to throw or hurl a projectile a great distance without the aid of explosive devices—particularly various types of ancient and medieval siege engines. Although the catapult has been used since ancient times, it has proven to be one of the most effective mechanisms during...
, most probably a seaborne variant of the Roman light catapult or onager
Onager (siege weapon)
The onager was a Roman siege engine, which derived its name from the kicking action of the machine, similar to that of an onager , it was created as a simpler, cheaper version of the ballista. The Onager is a type of catapult that uses torsional pressure, generally from twisted rope, to store...
. These were capable of hurling light loads—around 6 to 9 kg (13.2 to 19.8 lb)—a distance of 350–450 m (382.8–492.1 yd). Later technological improvements in machining
Machining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...
technology enabled the devising of a pump mechanism discharging a stream of burning fluid (flame thrower) at close ranges, devastating wooden ships in naval warfare
Naval warfare
Naval warfare is combat in and on seas, oceans, or any other major bodies of water such as large lakes and wide rivers.-History:Mankind has fought battles on the sea for more than 3,000 years. Land warfare would seem, initially, to be irrelevant and entirely removed from warfare on the open ocean,...
. Such weapons were also very effective on land when used against besieging forces.
Effectiveness and countermeasures
Although the destructiveness of Greek fire is indisputable, it should not be seen as some sort of "wonder weapon", nor did it make the Byzantine navyByzantine navy
The Byzantine navy was the naval force of the East Roman or Byzantine Empire. Like the empire it served, it was a direct continuation from its imperial Roman predecessor, but played a far greater role in the defense and survival of the state then its earlier iterations...
invincible. It was not, in the words of naval historian John Pryor, a "ship-killer" comparable to the naval ram
Naval ram
A naval ram was a weapon carried by varied types of ships, dating back to antiquity. The weapon consisted of an underwater prolongation of the bow of the ship to form an armoured beak, usually between six and twelve feet in length...
, which by then had fallen out of use. While Greek fire remained a potent weapon, its limitations were significant when compared to more traditional forms of artillery: in its siphon-deployed version, it had a limited range, and it could be used safely only in a calm sea and with favourable wind conditions. The enemy Muslim navies eventually adapted themselves to it, by staying out of its effective range and devising methods of protection such as felt or hides soaked in vinegar.
External links
- "Technoporn: Greek Fire". Wired Blog. December 29, 2006.
- Greek Fire – The Best Kept Secret of the Ancient World. By Richard Groller.