Defensive wall - AbsoluteAstronomy.com

A defensive wall is a fortification

Fortification

Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs...

used to protect a city or settlement from potential aggressors. In ancient to modern times, they were used to enclose settlements. Generally, these are referred to as city walls or town walls, although there were also wall

Wall

A wall is a usually solid structure that defines and sometimes protects an area. Most commonly, a wall delineates a building and supports its superstructure, separates space in buildings into rooms, or protects or delineates a space in the open air...

s, such as the Great Wall of China

Great Wall of China

The Great Wall of China is a series of stone and earthen fortifications in northern China, built originally to protect the northern borders of the Chinese Empire against intrusions by various nomadic groups...

, Hadrian's Wall

Hadrian's Wall

Hadrian's Wall was a defensive fortification in Roman Britain. Begun in AD 122, during the rule of emperor Hadrian, it was the first of two fortifications built across Great Britain, the second being the Antonine Wall, lesser known of the two because its physical remains are less evident today.The...

, and the metaphorical Atlantic Wall

Atlantic Wall

The Atlantic Wall was an extensive system of coastal fortifications built by Nazi Germany between 1942 and 1944 along the western coast of Europe as a defense against an anticipated Allied invasion of the mainland continent from Great Britain.-History:On March 23, 1942 Führer Directive Number 40...

, which extended far beyond the borders of a city

City

A city is a relatively large and permanent settlement. Although there is no agreement on how a city is distinguished from a town within general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.For example, in the U.S...

and were used to enclose regions or mark territorial boundaries. Beyond their defensive utility many walls also had important symbolic functions — representing the status and independence of the communities they embraced.

Existing ancient walls are almost always masonry

Masonry

Masonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...

structures, although brick and timber-built variants are also known. Depending on the topography

Topography

Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...

of the area surrounding the city or the settlement the wall is intended to protect, elements of the terrain (e.g. rivers or coastlines) may be incorporated in order to make the wall more effective.

Walls may only be crossed by entering the appropriate city gate

City Gates

-Track listing:# "Mingus Metamorphosis" 13:20# "Samba For Now" – 8:31# "Thank You Very Much Mr. Monk" – 7:57# "Nobody Knows the Trouble I've Seen" – 5:18# "City Gates" – 7:56...

and are often supplemented with tower

Tower

A tower is a tall structure, usually taller than it is wide, often by a significant margin. Towers are distinguished from masts by their lack of guy-wires....

s. In the Middle Ages, the right of a settlement to build a defensive wall was a privilege, and was usually granted by the so-called "right of crenellation" on a medieval fortification

Medieval fortification

Medieval fortification is military methods of Medieval technology that covers the development of fortification construction and use in Europe roughly from the fall of the Western Roman Empire to the Renaissance...

. The practice of building these massive walls, though having its origins in prehistory, was refined during the rise of city-state

City-state

A city-state is an independent or autonomous entity whose territory consists of a city which is not administered as a part of another local government.-Historical city-states:...

s, and energetic wall-building continued into the medieval period and beyond in certain parts of Europe.

History

From very early history to modern times, walls have been a near necessity for every city.
Uruk

Uruk

Uruk was an ancient city of Sumer and later Babylonia, situated east of the present bed of the Euphrates river, on the ancient dry former channel of the Euphrates River, some 30 km east of modern As-Samawah, Al-Muthannā, Iraq.Uruk gave its name to the Uruk...

in ancient Sumer

Sumer

Sumer was a civilization and historical region in southern Mesopotamia, modern Iraq during the Chalcolithic and Early Bronze Age....

(Mesopotamia

Mesopotamia

Mesopotamia is a toponym for the area of the Tigris–Euphrates river system, largely corresponding to modern-day Iraq, northeastern Syria, southeastern Turkey and southwestern Iran.Widely considered to be the cradle of civilization, Bronze Age Mesopotamia included Sumer and the...

) is one of the world's oldest known walled cities. Before that, the city (or rather proto-city

Proto-city

Proto-city is a term usually used to describe large villages or towns of the Neolithic Period such as Jericho and Catal Huyuk, but also any prehistoric settlement which has both rural and urban features, in an attempt to distinguish them from cities in later periods. Predynastic Egypt and Ubaid...

) of Jericho

Jericho

Jericho ; is a city located near the Jordan River in the West Bank of the Palestinian territories. It is the capital of the Jericho Governorate and has a population of more than 20,000. Situated well below sea level on an east-west route north of the Dead Sea, Jericho is the lowest permanently...

in what is now the West Bank

West Bank

The West Bank ) of the Jordan River is the landlocked geographical eastern part of the Palestinian territories located in Western Asia. To the west, north, and south, the West Bank shares borders with the state of Israel. To the east, across the Jordan River, lies the Hashemite Kingdom of Jordan...

had a wall

PPNA Wall of Jericho

The Wall of Jericho is a Pre-Pottery Neolithic A defensive or flood protection wall suggested to date to approximately 8000 BC.-Biblical story:...

surrounding it as early as the 8th millennium BC.

The Assyrians deployed large labour forces to build new palaces, temples and defensive walls.

Some settlements in the Indus Valley Civilization

Indus Valley Civilization

The Indus Valley Civilization was a Bronze Age civilization that was located in the northwestern region of the Indian subcontinent, consisting of what is now mainly modern-day Pakistan and northwest India...

were also fortified. By about 3500 B.C., hundreds of small farming villages dotted the Indus floodplain. Many of these settlements had fortifications and planned streets. The stone and mud brick houses of Kot Diji

Kot Diji

The ancient site at Kot Diji was the forerunner of the Indus Civilization. The people of this site lived about 3000 BCE. The remains consist of two parts; the citadel area on high ground , and outer area...

were clustered behind massive stone flood dykes and defensive walls, for neighboring communities quarreled constantly about the control of prime agricultural land. Mundigak (c. 2500 B.C.) in present day south-east Afghanistan

Afghanistan

Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world...

has defensive walls and square bastions of sun dried bricks.

Babylon

Babylon

Babylon was an Akkadian city-state of ancient Mesopotamia, the remains of which are found in present-day Al Hillah, Babil Province, Iraq, about 85 kilometers south of Baghdad...

was one of the most famous cities of the ancient world, especially as a result of the building program of Nebuchadnezzar

Nebuchadnezzar

Nebuchadnezzar was the name of several kings of Babylonia.* Nebuchadnezzar I, who ruled the Babylonian Empire in the 12th century BC* Nebuchadnezzar II , the Babylonian ruler mentioned in the biblical Book of Daniel...

, who expanded the walls and built the Ishtar Gate

Ishtar Gate

The Ishtar Gate was the eighth gate to the inner city of Babylon. It was constructed in about 575 BC by order of King Nebuchadnezzar II on the north side of the city....

.

Exceptions were few — notably, ancient Sparta

Sparta

Sparta or Lacedaemon, was a prominent city-state in ancient Greece, situated on the banks of the River Eurotas in Laconia, in south-eastern Peloponnese. It emerged as a political entity around the 10th century BC, when the invading Dorians subjugated the local, non-Dorian population. From c...

and ancient Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

did not have walls for a long time, choosing to rely on their militaries for defense instead. Initially, these fortifications were simple constructions of wood and earth, which were later replaced by mixed constructions of stones piled on top of each other without mortar

Mortar (masonry)

Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...

.

In Central Europe, the Celts built large fortified settlements known as oppida

Oppidum

Oppidum is a Latin word meaning the main settlement in any administrative area of ancient Rome. The word is derived from the earlier Latin ob-pedum, "enclosed space," possibly from the Proto-Indo-European *pedóm-, "occupied space" or "footprint."Julius Caesar described the larger Celtic Iron Age...

, whose walls seem partially influenced by those built in the Mediterranean.
The fortifications were continuously expanded and improved.

In ancient Greece

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

, large stone walls had been built in Mycenaean Greece

Mycenaean Greece

Mycenaean Greece was a cultural period of Bronze Age Greece taking its name from the archaeological site of Mycenae in northeastern Argolis, in the Peloponnese of southern Greece. Athens, Pylos, Thebes, and Tiryns are also important Mycenaean sites...

, such as the ancient site of Mycenae

Mycenae

Mycenae is an archaeological site in Greece, located about 90 km south-west of Athens, in the north-eastern Peloponnese. Argos is 11 km to the south; Corinth, 48 km to the north...

(famous for the huge stone blocks of its 'cyclopean' walls). In classical era Greece, the city of 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...

built a long set of parallel stone walls called the Long Walls

Long Walls

The Long Walls , in Ancient Greece, were walls built from a city to its port, providing a secure connection to the sea even during times of siege. Although long walls were built at several locations in Greece—Corinth and Megara being two of the best known examples—the phrase "long...

that reached their guarded seaport at Piraeus

Piraeus

Piraeus is a city in the region of Attica, Greece. Piraeus is located within the Athens Urban Area, 12 km southwest from its city center , and lies along the east coast of the Saronic Gulf....

.

Large tempered earth (i.e. rammed earth

Rammed earth

Rammed earth, also known as taipa , tapial , and pisé , is a technique for building walls using the raw materials of earth, chalk, lime and gravel. It is an ancient building method that has seen a revival in recent years as people seek more sustainable building materials and natural building methods...

) walls were built in ancient China since the Shang Dynasty

Shang Dynasty

The Shang Dynasty or Yin Dynasty was, according to traditional sources, the second Chinese dynasty, after the Xia. They ruled in the northeastern regions of the area known as "China proper" in the Yellow River valley...

(c. 1600-1050 BC), as the capital at ancient Ao had enormous walls built in this fashion (see siege

Siege

A siege is a military blockade of a city or fortress with the intent of conquering by attrition or assault. The term derives from sedere, Latin for "to sit". Generally speaking, siege warfare is a form of constant, low intensity conflict characterized by one party holding a strong, static...

for more info). Although stone walls were built in China during the Warring States (481-221 BC), mass conversion to stone architecture did not begin in earnest until the Tang Dynasty

Tang Dynasty

The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

(618-907 AD). In terms of China's longest and most impressive fortification, the Great Wall had been built since the Qin Dynasty

Qin Dynasty

The Qin Dynasty was the first imperial dynasty of China, lasting from 221 to 207 BC. The Qin state derived its name from its heartland of Qin, in modern-day Shaanxi. The strength of the Qin state was greatly increased by the legalist reforms of Shang Yang in the 4th century BC, during the Warring...

(221-207 BC), although its present form was mostly an engineering feat and remodeling of the Ming Dynasty

Ming Dynasty

The Ming Dynasty, also Empire of the Great Ming, was the ruling dynasty of China from 1368 to 1644, following the collapse of the Mongol-led Yuan Dynasty. The Ming, "one of the greatest eras of orderly government and social stability in human history", was the last dynasty in China ruled by ethnic...

(1368-1644 AD) during the 15th and 16th centuries. The large walls of Pingyao

Pingyao

Pingyao is a Chinese city and county in central Shanxi province, China. It lies about 715 km from Beijing and 80 km from the provincial capital, Taiyuan. During the Qing Dynasty, Pingyao was a financial center of China...

serve as one example. Likewise, the famous walls of the Forbidden City

Forbidden City

The Forbidden City was the Chinese imperial palace from the Ming Dynasty to the end of the Qing Dynasty. It is located in the middle of Beijing, China, and now houses the Palace Museum...

in Beijing

Beijing

Beijing , also known as Peking , is the capital of the People's Republic of China and one of the most populous cities in the world, with a population of 19,612,368 as of 2010. The city is the country's political, cultural, and educational center, and home to the headquarters for most of China's...

were established in the early 15th century by the Yongle Emperor

Yongle Emperor

The Yongle Emperor , born Zhu Di , was the third emperor of the Ming Dynasty of China from 1402 to 1424. His Chinese era name Yongle means "Perpetual Happiness".He was the Prince of Yan , possessing a heavy military base in Beiping...

.

The Romans

Ancient Rome

Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

fortified their cities with massive, mortar-bound stone walls.
The most famous of these are the largely extant Aurelian Walls

Aurelian Walls

The Aurelian Walls is a line of city walls built between 271 and 275 in Rome, Italy, during the reign of the Roman Emperors Aurelian and Probus....

of Rome

Rome

and the Theodosian Walls 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:...

, together with partial remains elsewhere. These are mostly city gates, like the Porta Nigra

Porta Nigra

The Porta Nigra is a large Roman city gate in Trier, Germany. It is today the largest Roman city gate north of the Alps and has been designated a World Heritage Site....

in Trier

Trier

Trier, historically called in English Treves is a city in Germany on the banks of the Moselle. It is the oldest city in Germany, founded in or before 16 BC....

or Newport Arch

Newport Arch

Newport Arch is the name given to the remains of a 3rd century Roman gate in the city of Lincoln, Lincolnshire. It is reputedly the oldest arch in the United Kingdom still used by traffic.- History :...

in Lincoln

Lincoln, Lincolnshire

Lincoln is a cathedral city and county town of Lincolnshire, England.The non-metropolitan district of Lincoln has a population of 85,595; the 2001 census gave the entire area of Lincoln a population of 120,779....

.

Apart from these, the early Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

also saw the creation of some towns built around castles. These cities were only rarely protected by simple stone walls and more usually by a combination of both walls and ditches

Ditch (fortification)

A ditch in military engineering is an obstacle, designed to slow down or break up an attacking force, while a trench is intended to provide cover to the defenders...

.
From the 12th century AD hundreds of settlements of all sizes were founded all across Europe, who very often obtained the right of fortification soon afterwards.

The founding of urban centers was an important means of territorial expansion and many cities, especially in eastern Europe, were founded precisely for this purpose during the period of Eastern Colonisation

History of German settlement in Eastern Europe

The presence of German-speaking populations in Central and Eastern Europe is rooted in centuries of history, with the settling in northeastern Europe of Germanic peoples predating even the founding of the Roman Empire...

. These cities are easy to recognise due to their regular layout and large market spaces. The fortifications of these settlements were continuously improved to reflect the current level of military development.

During the Renaissance era, the Venetians raised great walls around cities threatened by the Ottoman empire. Among the finest examples are the walled cities of Nicosia

Nicosia

Nicosia from , known locally as Lefkosia , is the capital and largest city in Cyprus, as well as its main business center. Nicosia is the only divided capital in the world, with the southern and the northern portions divided by a Green Line...

and Famagusta

Famagusta

Famagusta is a city on the east coast of Cyprus and is capital of the Famagusta District. It is located east of Nicosia, and possesses the deepest harbour of the island.-Name:...

in Cyprus

Cyprus

Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...

and the fortifications of Candia

Heraklion

Heraklion, or Heraclion is the largest city and the administrative capital of the island of Crete, Greece. It is the 4th largest city in Greece....

and Chania

Chania

Chaniá , , also transliterated Chania, Hania, and Xania, older form Chanea and Venetian Canea, Ottoman Turkish خانيه Hanya) is the second largest city of Crete and the capital of the Chania peripheral unit...

in Crete

Crete

Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

, which still stand to this day.

Composition

At its most simple, a defensive wall consists of a wall enclosure and its gates. For the most part, the top of the walls were accessible, with the outside of the walls having tall parapet

Parapet

A parapet is a wall-like barrier at the edge of a roof, terrace, balcony or other structure. Where extending above a roof, it may simply be the portion of an exterior wall that continues above the line of the roof surface, or may be a continuation of a vertical feature beneath the roof such as a...

s with embrasure

Embrasure

In military architecture, an embrasure is the opening in a crenellation or battlement between the two raised solid portions or merlons, sometimes called a crenel or crenelle...

s or merlon

Merlon

In architecture, a merlon forms the solid part of an embattled parapet, sometimes pierced by embrasures. The space between two merlons is usually called a crenel, although those later designed and used for cannons were called embrasures.-Etymology:...

s. North of the Alps, this passageway at the top of the walls occasionally had a roof.

In addition to this, many different enhancements were made over the course of the centuries:

City ditch: a ditch dug in front of the walls, occasionally filled with water.
Gate tower
Gate tower
A gate tower is a tower built over or next to a major gateway.Usually it is part of a medieval fortification. This may be a town or city wall, a fortress or a castle. The gate tower may be built as a twin tower on either side of an entranceway. Even in the design of modern building complexes, gate...

: a tower built next to, or on top of the city gates to better defend the city gates.
Wall tower: a tower built on top of a segment of the wall, which usually extended outwards slightly, so as to be able to observe the exterior of the walls on either side. In addition to arrow slits, ballistae, catapults and cannons could be mounted on top for extra defence.
Pre-wall: wall built outside the wall proper, usually of lesser height — the space in between was usually further subdivided by additional walls.
Additional obstacles in front of the walls.

The defensive towers of west and south European fortifications in the Middle Ages were often very regularly and uniformly constructed (cf. Ávila, Provins

Provins

Provins is a commune in the Seine-et-Marne department in the Île-de-France region in north-central France.Provins, a town of medieval fairs, became a UNESCOWorld Heritage Site in 2001.-Administration:...

), whereas Central European
city walls tend to show a variety of different styles.
In these cases the gate and wall towers often reach up to considerable heights, and gates equipped with two towers on either side are much rarer.
Apart from having a purely military and defensive purpose, towers also played a representative and artistic role in the conception of a fortified complex. The architecture of the city thus competed with that of the castle of the noblemen and city walls were often a manifestation of the pride of a particular city.

Urban areas outside the city walls, so-called Vorstädte

Vorstadt

Vorstadt is a German term that describes an area of a city, outside the Altstadt or the city centre, but tightly connected to it and densely populated, thus distinguished from Vororte....

, were often enclosed by their own set of walls and integrated into the defense of the city. These areas were often inhabited by the poorer population and held the "noxious trades". In many cities, a new wall was built once the city had grown outside of the old wall. This can often still be seen in the layout of the city, for example in Nördlingen

Nördlingen

Nördlingen is a town in the Donau-Ries district, in Bavaria, Germany, with a population of 20,000. It is located in the middle of a complex meteorite crater, called the Nördlinger Ries. The town was also the place of two battles during the Thirty Years' War...

, and sometimes even a few of the old gate towers are preserved, such as the white tower in Nuremberg

Nuremberg

Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...

.
Additional constructions prevented the circumvention of the city, through which many important trade routes passed, thus ensuring that tolls were paid when the caravans passed through the city gates, and that the local market was visited by the trade caravans.
Furthermore, additional signaling and observation towers were frequently built outside the city, and were sometimes fortified in a castle-like fashion. The border of the area of influence of the city was often partially or fully defended by elaborate ditches, walls and/or hedges.
The crossing points were usually guarded by gates or gate houses.
These defenses were regularly checked by riders, who often also served as the gate keepers. Long stretches of these defenses can still be seen to this day, and even some gates are still intact.
To further protect their territory, rich cities also established castles in their area of influence.
A famous example of this practice is the Romanian "Dracula Castle

Bran Castle

Bran Castle , situated near Bran and in the immediate vicinity of Braşov, is a national monument and landmark in Romania. The fortress is situated on the border between Transylvania and Wallachia, on DN73...

" at Bran/Törzburg, which was intended to protect Kronstadt (today's Braşov

Brasov

Brașov is a city in Romania and the capital of Brașov County.According to the last Romanian census, from 2002, there were 284,596 people living within the city of Brașov, making it the 8th most populated city in Romania....

).

The city walls were often connected to the fortifications of hill castles via additional walls .
Thus the defenses were made up of city and castle fortifications taken together. Several examples of this are preserved, for example in Germany Hirschhorn

Hirschhorn (Neckar)

Hirschhorn is a small town in the Bergstraße district of Hesse, Germany, and is known as "The Pearl of the Neckar valley”. Hirschhorn is a climatic health resort situated in the Geo-Naturpark Bergstraße-Odenwald.- Location :...

on the Neckar, Königsberg

Königsberg

Königsberg was the capital of East Prussia from the Late Middle Ages until 1945 as well as the northernmost and easternmost German city with 286,666 inhabitants . Due to the multicultural society in and around the city, there are several local names for it...

and Pappenheim

Pappenheim

Pappenheim is a town in the Weißenburg-Gunzenhausen district, in Bavaria, Germany. It is situated on the river Altmühl, 11 km south of Weißenburg in Bayern.- Notable people :The architect and professor Eduard Mezger was born in Pappenheim....

, Franken, Burghausen

Burghausen

Burghausen may refer to several places in Germany:*Burghausen, Altötting, a town in southeastern Bavaria*Burghausen bei Münnerstadt, part of Münnerstadt in northern Bavaria*Burghausen bei Freising, part of Kirchdorf an der Amper in central Bavaria...

in Oberbayern and many more.
A few castles were more directly incorporated into the defensive strategy of the city (e.g. Nuremberg

Nuremberg

, Zons

Zons

Zons, or Feste Zons is an old city in the Rhein-Kreis Neuss, Germany. It is now a part of the city of Dormagen since 1975. In 2006 its population was 5,405 .- History :...

, Carcassonne

Carcassonne

Carcassonne is a fortified French town in the Aude department, of which it is the prefecture, in the former province of Languedoc.It is divided into the fortified Cité de Carcassonne and the more expansive lower city, the ville basse. Carcassone was founded by the Visigoths in the fifth century,...

), or the cities were directly outside the castle as a sort of "pre-castle" (Coucy-le-Chateau, Conwy

Conwy

Conwy is a walled market town and community in Conwy County Borough on the north coast of Wales. The town, which faces Deganwy across the River Conwy, formerly lay in Gwynedd and prior to that in Caernarfonshire. Conwy has a population of 14,208...

and others). Larger cities often had multiple stewards — for example Augsburg

Augsburg

Augsburg is a city in the south-west of Bavaria, Germany. It is a university town and home of the Regierungsbezirk Schwaben and the Bezirk Schwaben. Augsburg is an urban district and home to the institutions of the Landkreis Augsburg. It is, as of 2008, the third-largest city in Bavaria with a...

was divided into a Reichstadt and a bishopal (clerical) city. These different parts were often separated by their own fortifications.

With the development of firearms came the necessity to expand the existing installation, which occurred in multiples stages. Firstly, additional, half-circular towers were added in the interstices between the walls and pre-walls (s.a.) in which a handful of cannon

Cannon

A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellents to launch a projectile. Cannon vary in caliber, range, mobility, rate of fire, angle of fire, and firepower; different forms of cannon combine and balance these attributes in varying degrees,...

s could be placed. Soon after, reinforcing structures — or "bastion

Bastion

A bastion, or a bulwark, is a structure projecting outward from the main enclosure of a fortification, situated in both corners of a straight wall , facilitating active defence against assaulting troops...

s" — were added in strategically relevant positions, e.g. at the gates or corners. A well-preserved example of this is the Spitalbastei in Rothenburg or the bastions built as part of the 17th-century walls surrounding Derry

Derry

Derry or Londonderry is the second-biggest city in Northern Ireland and the fourth-biggest city on the island of Ireland. The name Derry is an anglicisation of the Irish name Doire or Doire Cholmcille meaning "oak-wood of Colmcille"...

, a city in Ulster

Ulster

Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial...

in the north of Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

; however, at this stage the cities were still only protected by relatively thin walls which could offer little resistance to the cannons of the time. Therefore new, star fort

Star fort

A star fort, or trace italienne, is a fortification in the style that evolved during the age of gunpowder, when cannon came to dominate the battlefield, and was first seen in the mid-15th century in Italy....

s with numerous cannons and thick earth walls reinforced by stone were built. These could resist cannon fire for prolonged periods of time. However, these massive fortifications severely limited the growth of the cities, as it was much more difficult to move them as compared to the simple walls previously employed — to make matters worse, it was forbidden to build "outside the city gates" for strategic reasons and the cities became more and more densely populated as a result.

Decline

In the wake of city growth and the ensuing change of defensive strategy, focusing more on the defense of forts around cities, most city walls were demolished. Also, the invention of gunpowder rendered walls less effective, as siege cannons could then be used to blast through walls, allowing armies to simply walk through. Nowadays, the presence of former city fortifications can often only be deduced from the presence of ditches or parks.

Furthermore, some street names hint at the presence of fortifications in times past, for example when words such as "wall" or "glacis" occur.

In the 19th century, less emphasis was placed on preserving the fortifications for the sake of their architectural or historical value — on the one hand, complete fortifications were restored (Carcassonne

Carcassonne

), on the other hand many structures were demolished in an effort to modernize the cities. A notable exception in this is the "monument preservation" law by the Bavarian King Ludwig I of Bavaria

Ludwig I of Bavaria

Ludwig I was a German king of Bavaria from 1825 until the 1848 revolutions in the German states.-Crown prince:...

, which led to the nearly complete preservation of many impressive monuments such as the Rothenburg ob der Tauber

Rothenburg ob der Tauber

Rothenburg ob der Tauber is a town in the district of Ansbach of Mittelfranken , the Franconia region of Bavaria, Germany, well known for its well-preserved medieval old town, a destination for tourists from around the world. In the Middle Ages, it was an Imperial Free City...

, Nördlingen

Nördlingen

and Dinkelsbühl

Dinkelsbühl

Dinkelsbühl is a historic city in Bavaria, Germany and a former Free imperial city of the Holy Roman Empire. Now it belongs to the district of Ansbach, north of Aalen.-History:...

.
The countless small fortified towns in the Franken

Franken

Franken may refer to:*Franks, medieval Germanic tribes*Franconia, a region in Bavaria, Germany*Franconia , one of the 13 wine regions of Germany*Franken, Haut-Rhin, a commune of the Haut-Rhin département of France*Franc, a currency unit...

region were also preserved as a consequence of this edict.

Modern era

Walls and fortified wall structures were still built in the modern era. They did not, however, have the original purpose of being a structure able to resist a prolonged siege or bombardment.

Berlin's city wall from the 1730s to the 1860s was partially made of wood. Its primary purpose was to enable the city to impose tolls on goods and, secondarily, also served to prevent the desertion of soldiers from the garrison in Berlin.

The Berlin Wall

Berlin Wall

The Berlin Wall was a barrier constructed by the German Democratic Republic starting on 13 August 1961, that completely cut off West Berlin from surrounding East Germany and from East Berlin...

was a different form of wall

Separation barrier

A separation barrier is a wall or fence constructed to limit the movement of people across a certain line or border, or to separate two populations. These structures vary in placement with regard to international borders and topography...

, in that it did not exclusively serve the purpose of protection of an enclosed settlement. One of its purposes was to prevent the crossing of the Berlin border between the GDR

German Democratic Republic

The German Democratic Republic , informally called East Germany by West Germany and other countries, was a socialist state established in 1949 in the Soviet zone of occupied Germany, including East Berlin of the Allied-occupied capital city...

and the West German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

exclave of west-Berlin.

Defensive walls have been built in Korea along the De-militarised Zone.

In the 20th century and after, many enclaves Jewish settlements in Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

were and are surrounded by fortified walls, as are many parts of Belfast

Belfast

Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...

, Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

by the Belfast Peace Lines.

Additionally, in some countries, different embassies may be grouped together in a single "embassy district," enclosed by a fortified complex with walls and towers — this usually occurs in regions where the embassies run a high risk of being target of attacks. An early example of such a compound was the Legation Quarter

Beijing Legation Quarter

The Peking Legation Quarter was the area in Peking where a number of foreign legations were located between 1861 and 1959. In Chinese, the area is known as Dōng jiāomín xiàng , which is the name of the hutong running through the area...

in Beijing

Beijing

in the late 19th and early 20th centuries.

Most of these "modern" city walls are made of steel and concrete. Vertical concrete plates are put together so as to allow the least space in between them, and are rooted firmly in the ground.
The top of the wall is often protruding and beset with barbed wire

Barbed wire

Barbed wire, also known as barb wire , is a type of fencing wire constructed with sharp edges or points arranged at intervals along the strand. It is used to construct inexpensive fences and is used atop walls surrounding secured property...

in order to make climbing them more difficult. These walls are usually built in straight lines and covered by watchtowers at the corners. Double walls, i.e. two walls with an interstitial "zone of fire" (cf. the Berlin wall) are rare.

The only extant city walls in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

are the historic ones in Old Quebec City

Quebec City

Quebec , also Québec, Quebec City or Québec City is the capital of the Canadian province of Quebec and is located within the Capitale-Nationale region. It is the second most populous city in Quebec after Montreal, which is about to the southwest...

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

History

Composition

Decline

Modern era

See also