) were the elite cavalry
of the Macedonian army
from the time of king Philip II of Macedon
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
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
, a festival pertaining to the sacred relationship which bound the king and his companions together
was celebrated and even Euripides
, the famed Athenian play writer, was honoured as an hetairos
of the king Archelaus
The Royal friends (Philoi
) or the king's Companions (basilikoi hetairoi) were named for life by the king among the Macedonian aristocracy.
Companion cavalry would ride the best horses, and receive the best weaponry available. In Alexander's day, each carried a xyston
, and wore a bronze cuirass
, shoulder guards and Boeotian helmets, but bore no shield.
(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.
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
During the advance on Granicus, a squadron commanded by Socrates
hailed from Apollonia on Lake Bolbe.
During the Battle of Issus Arrian
names the ile of Anthemus
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
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.
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
tactic: the Companion cavalry would be used as a hammer, in conjunction with the Macedonian phalanx
, which acted as their anvil. The phalanx
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
, 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.
From War and Game:
All the Macedonian heavy cavalry – 1,800 men in all – was in the senior regiment of the army, its riders recruited from among the sons of the noblest Macedonian families. The regiment consisted of eight squadrons (ile), of 200 men each; only the royal one had 400, and these were the crème de la crème. A squadron was divided into four smaller units: tetrarchia, each with 49 men. Squadrons were commanded by an ilearch, and were probably accompanied by a trumpeter.
The figure of 49 was decided very simply: the tetrarch was at the head of the unit, with three men in the first line behind him, five in the second, seven in the third and so on up to the last, which had 13 men. This triangular formation was introduced into the Macedonian army by Philip II. It had the advantage of making possible sudden turns to the left or right, at some 45 degrees, which gave the unit more manouverability than the line formation used by the Persian cavalry. There was no need for the whole unit to turn; each man just turned half-left or half-right, and the left or right side of the triangle became the new front line of the unit, with seven Companions (heteroi), in the first line and six in the second. The men in the first line were spaced, so those in the second line were not hindered in the charge. This gave the tetrarchia a striking front line of 13 men, and 52 for the whole ile. The four tetrarchias in an ile were arranged like the teeth of a saw, one beside the other, so did not present each other with obstacles to straight or diagonal movement. Several iles made up a cavalry brigade (hipparchy) commanded by a hipparch. The execution of their complex manoeuvres in battle conditions required strong discipline and a high level of training.
Each squadron of the Companions was recruited from its county and bore its name, and probably had its distinctive colours too. Equipment and weaponry did not differ much from the Greek, but the helmet was distinctly Macedonian. Later, during campaigns lasting several years, lost equipment was made good in various ways, and the appearance of the men became Hellenic. Alexander himself had his helmet damaged by an axe blow from a Persian rider at the Battle of Granicus, and replaced it with a Boeotian helmet.
In ancient times, lions and leopards lived in Macedonia and are mentioned by Roman sources several centuries later. Macedonians and Thracians covered their horses with the skins of these beasts, as we can still see in stone reliefs, which have been preserved. Macedonian Companion (Heteroi)Cavalryman circa 330BC « War and Game
And now for some projects I was working on.
An organization chart based on my information.
A digital drawing on a companion Tetrarchia in a classic triangle formation, with Alexnader at the tip of the spear (the drawing is historically inaccurate of course, the Xystons should be much longer, I doubt they got close, and none of them should be holding shields - you get the idea though)
Horse art courtest of Junior general. Junior General Home Page Regiment (Ilae) list:
1)Royal Ila - Commanded by Alexander and?
2)Apollonia - Commanded by Socrates and?
3)Anthemus - Commanded by?
4)Leuge - Commanded by?