Hetairoi

The Companions (Greek: ἑταῖροι, hetairoi) were the elite cavalry of the Macedonian army from the time of king Philip II of Macedon and achieved their greatest 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 muscle cuirass or linothorax, shoulder guards and Boeotian helmets, but bore no shield. A kopis (curved slashing sword) or xiphos (cut and thrust sword) was also carried for close combat, should the xyston break.

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 the other units contained, c. 400. These cavalry squadrons would sometimes be combined together in groups of two, three or four to form a hipparchy, which was commanded by a hipparch, though the whole Companion force was generally commanded by Alexander.

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