The Companions were the elite cavalry

Cavalry

Cavalry or horsemen were soldiers or warriors who fought mounted on horseback. Cavalry were historically the third oldest and the most mobile of the combat arms...

 of the Macedonian army from the time of king Philip II of Macedon

Philip II of Macedon

Philip II of Macedon "friend" + ἵππος "horse" — transliterated ; 382 – 336 BC), was a king of Macedon from 359 BC until his assassination in 336 BC. He was the father of Alexander the Great and Philip III.-Biography:...

 and reached the most prestige under Alexander the Great, and have been regarded as the best cavalry in the ancient world and the first shock cavalry. Chosen Companions/Hetairoi formed the elite guard of the king (Somatophylakes

Somatophylakes

Somatophylakes , in its literal English translation from Greek, means "bodyguards".The most famous body of somatophylakes were those of Philip of Macedon and Alexander the Great. They consisted of seven men, drawn from the Macedonian nobility, who also acted as high-ranking military officers,...

).

Etymology

The name of the military unit derives from the Hetairoi, those near the king. The Hetairoi (Companions) could be members of the Macedonian aristocracy or commoners of any Greek origin who enjoyed the trust and friendship of the Macedonian regent. The Hetairideia

Hetairideia

Hetaeridia or Hetairidia was a name of a festival among Macedonians and Magnesians . The origin of the Thessalian Hetaeridia is said to be related to Jason, who sacrificed to Zeus Hetaereius, "Zeus of the Companions" and called the festival by this name...

, a festival pertaining to the sacred relationship which bound the king and his companions together was celebrated and even Euripides

Euripides

Euripides was one of the three great tragedians of classical Athens, the other two being Aeschylus and Sophocles. Some ancient scholars attributed ninety-five plays to him but according to the Suda it was ninety-two at most...

, the famed Athenian play writer, was honoured as an hetairos of the king Archelaus

Archelaus I of Macedon

Archelaus I was a king of Macedon from 413 to 399 BC. He was a capable and beneficent ruler, known for the sweeping changes he made in state administration, the military, and commerce. By the time that he died, Archelaus had succeeded in converting Macedon into a significantly stronger power...

. The Royal friends (Philoi

Philoi

Philoi was a title to the royal friends, advisors of the king in ancient Macedonia. They were the personal choice of the king and they might have came from anywhere in the Greek world. The title became common among the Hellenistic kingdoms...

) or the king's Companions (basilikoi hetairoi) were named for life by the king among the Macedonian aristocracy.

Equipment

Companion cavalry would ride the best horses, and receive the best weaponry available. In Alexander's day, each carried a xyston

Xyston

Not to be confused with XystosThe xyston |javelin]]; pointed stick, goad") was a type of a long thrusting lance in ancient Greece. It measured about long and was probably held by the cavalryman with both hands, although the depiction of Alexander the Great's xyston on the Alexander Mosaic in...

, and wore a bronze cuirass

Cuirass

A cuirass is a piece of armour, formed of a single or multiple pieces of metal or other rigid material, which covers the front of the torso...

, shoulder guards and Boeotian helmets, but bore no shield. A kopis

Kopis

The kopis was a sword with a forward-curving blade, primarily used as a tool for cutting meat, for slaughter and animal sacrifice, but also as a weapon....

 (curved slashing sword) was also carried for close combat, should the xyston break. Their horses had a large amount of thick felt draped over their sides, while they probably had partial breast and head plating for protection against spears, missiles etc.

Organization

The Companion cavalry was composed of the Hetairoi of the king, mainly upper class citizens who were able to acquire and maintain armour and horses. In the age of Philip II and Alexander they were organized into 8 territorial squadrons, termed ilai. Each ile numbered between 200 and 300 horsemen and was commanded by two men, because as Arrian claims, Alexander "did not want anyone, not even his intimate friend, to be the centre of attention". After receiving reinforcements in Susa, Alexander established two companies in each squadron. They were referred to by the name of the territory they were mustered in or by the name of its captain. The Royal Ile was commanded by Alexander himself and contained twice the number of soldiers of the other units contained, c. 400. These cavalry squadrons would sometimes be combined together in groups of two, three or four to form hipparchy which were commanded by a hipparch, though the whole Companion force was generally commanded by Alexander.

In Alexander's Balkan campaigns, we find mentions of Companions from upper Macedonia, the central Macedonian plain and Amphipolis

Amphipolis

Amphipolis was an ancient Greek city in the region once inhabited by the Edoni people in the present-day region of Central Macedonia. It was built on a raised plateau overlooking the east bank of the river Strymon where it emerged from Lake Cercinitis, about 3 m. from the Aegean Sea. Founded in...

. During the advance on Granicus, a squadron commanded by Socrates

Socrates of Macedon

For other persons with the same name, see Socrates Socrates , son of Sathon was hipparch of the ile of Hetairoi from Apollonia , since at least the beginning of the Asiatic expedition.-References:...

 hailed from Apollonia on Lake Bolbe. During the Battle of Issus

Battle of Issus

The Battle of Issus occurred in southern Anatolia, in November 333 BC. The invading troops, led by the young Alexander of Macedonia, defeated the army personally led by Darius III of Achaemenid Persia in the second great battle for primacy in Asia...

 Arrian

Arrian

Lucius Flavius Arrianus 'Xenophon , known in English as Arrian , and Arrian of Nicomedia, was a Roman historian, public servant, a military commander and a philosopher of the 2nd-century Roman period...

 names the ile of Anthemus (modern Galatista), and another from the unidentified land of Leuge, likely Pieria are also mentioned.

Theopompus describes the Companions, probably of around the mid 4th century BC, as being made of "no more than 800 at this time" and mustered "some from Macedonia, some from Thessaly and still others from the rest of Greece". By 338 BC, Alexander is reported to have around 2600 in his Companion Cavalry. As Alexander's force campaigned towards India, barbarians played an increasing role in the Companion Cavalry and the Macedonian mutiny at Opis

Opis

Opis was an ancient Babylonian city on the Tigris, not far from modern Baghdad. The precise location of Opis has not been established, but from the Akkadian and Greek texts, it was located on the east bank of the Tigris, near the Diyala River.-History:Opis is mentioned for the first time at the...

 may have been partially caused by this. At one point there were four hipparchies made up of entirely oriental forces and one that was a mix of Macedonians and orientals.

Tactics and use

The Companions probably constituted the first real shock cavalry, able to conduct charges against massed infantry, even if such use is scarcely described in the ancient sources. Contemporary cavalry, even when more heavily armored, would most usually be equipped with javelins and would avoid melee.

In battle it would form part of a hammer and anvil

Hammer and anvil

The Hammer and Anvil tactic is a military tactic used since the beginning of organized warfare. It was used mostly in the ancient world, including by Alexander the Great.- The procedure :...

 tactic: the Companion cavalry would be used as a hammer, in conjunction with the Macedonian phalanx

Macedonian phalanx

The Macedonian phalanx is an infantry formation developed by Philip II and used by his son Alexander the Great to conquer the Persian Empire and other armies...

-based infantry

Infantry

Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...

, which acted as their anvil. The phalanx

Phalanx formation

The phalanx is a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar weapons...

 would pin the enemy in place, while the Companion cavalry would attack the enemy on the flank or from behind.

In battle, Alexander the Great personally led the charge at the head of the royal squadron of the Companion cavalry, usually in a wedge formation. In a pitched battle, the Companions usually fought on the right wing of the Macedonian army, next to the shield bearing guards, the Hypaspists

Hypaspists

A hypaspist is a squire, man at arms, or "shield carrier". In Homer, Deiphobos advances "ὑπασπίδια" or under cover of his shield. By the time of Herodotus the word had come to mean a high status soldier as is strongly suggested by Herodotus in one of the earliest known uses:"Now the horse which...

, who would guard the right flank of the phalanx. Other cavalry troops would protect the flanks of the Macedonian line during battle. Under Alexander's command, the Companions' role was decisive in most of his battles in Asia.

Hellenistic kingdoms

The Companion cavalry of the Diadochoi

Diadochi

The Diadochi were the rival generals, family and friends of Alexander the Great who fought for the control of Alexander's empire after his death in 323 BC...

 (Alexandrian successor-states), were even more heavily equipped. Seleucid

Seleucid Empire

The Seleucid Empire was a Greek-Macedonian state that was created out of the eastern conquests of Alexander the Great. At the height of its power, it included central Anatolia, the Levant, Mesopotamia, Persia, today's Turkmenistan, Pamir and parts of Pakistan.The Seleucid Empire was a major centre...

 Companions were noted to have worn lighter, but not otherwise dissimilar, equipment to the cataphract

Cataphract

A cataphract was a form of armored heavy cavalry utilised in ancient warfare by a number of peoples in Western Eurasia and the Eurasian Steppe....

s at the Battle of Magnesia

Battle of Magnesia

The Battle of Magnesia was fought in 190 BC near Magnesia ad Sipylum, on the plains of Lydia , between the Romans, led by the consul Lucius Cornelius Scipio and his brother, the famed general Scipio Africanus, with their ally Eumenes II of Pergamum against the army of Antiochus III the Great of the...

 in 190 BC, which may have included partial horse armour and leg and arm protection. Ptolemaic

Ptolemaic dynasty

The Ptolemaic dynasty, was a Macedonian Greek royal family which ruled the Ptolemaic Empire in Egypt during the Hellenistic period. Their rule lasted for 275 years, from 305 BC to 30 BC...

 Companions were also equipped with a large round aspis

Aspis

"Aspis" is the generic term for the word shield. The aspis, which is carried by Greek infantry of various periods, is often referred to as a hoplon .According to Diodorus Siculus:-Construction:...

cavalry shield unlike the Companions of Phillip and Alexander.
‘Companions’ was a title not used by the Seleucids in its original sense. It was replaced with different and various grades of ‘Kings Friends'. However, the title Companions was kept as a regimental one. There was only one regiment or unit that held the title of Companions in the entire Hellenistic world though; the Antigonids and Ptolemies had different names for their elite cavalry regiments.

Eastern Roman Empire

The Hetaireia or Hetaeria was a corps of bodyguards during 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...

. Its name means "the Company", echoing the ancient Macedonian

Macedon

Macedonia or Macedon was an ancient kingdom, centered in the northeastern part of the Greek peninsula, bordered by Epirus to the west, Paeonia to the north, the region of Thrace to the east and Thessaly to the south....

 Companion cavalry. The imperial Hetaireia was composed chiefly of foreigners. They acted as part of the Byzantine imperial guard

Imperial Guard

The Imperial Guard was originally a small group of elite soldiers of the French Army under the direct command of Napoleon I, but grew considerably over time. It acted as his bodyguard and tactical reserve, and he was careful of its use in battle...

 alongside the tagmata

Tagma (military)

The tagma is a term for a military unit of battalion or regiment size. The best-known and most technical use of the term however refers to the elite regiments formed by Byzantine emperor Constantine V and comprising the central army of the Byzantine Empire in the 8th–11th centuries.-History and...

in the 9th–12th centuries.