Companion cavalry

The Companions (εταιροι hetairoi) were the cavalry of the Macedonian army from the time of king Philip II of Macedon, and also formed the elite guard of the king. In battle they would be used as the hammer, in conjunction with the Macedonian phalanx-based infantry, which acted as the anvil. The phalanx would "fix" (pin) the enemy in place, and the Companion cavalry would attack the enemy on the flank or from behind. It should be noted that the Macedonian kings also employed other cavalry types, which were often deployed on the left flank. The companions were a heavier, better armed unit, made up mainly of noblemen. They probably constituted the first real shock cavalry, able to conduct charges against massed infantry. Contemporary cavalry, even when more heavily armored, would most usually be equipped with javelins and would avoid melee.

In the battles of Alexander the Great, son of Philip II, he would personally lead the charge at the head of the royal squadron of 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 guard, the Hypaspists, normally positioning the phalanx in the center. The various cavalry troops would protect the flanks of the Macedonian line during battle. As heavy cavalry, the Companions were Alexander's decisive arm in battle.

The Companions were organized into territorial squadrons, made of 200 to 300 soldiers. In Alexander's campaign into Persia, there were eight squadrons, commanded by Philotas, with one being the royal squadron. Philip II of Macedon enlarged the size of the unit to around 2000 soldiers, as opposed to the 600 used as a mounted bodyguard for the king in battle.

They would ride the best horses, and receive the best weaponry available. In Alexander's day, each carried a xyston (a lance), and wore a bronze or iron breastplate and helmet. A kopis (curved slashing sword) was also carried for melee combat, should the xyston break. Their horses had a large amount of thick felt draped over their sides like cataphracts' scale, while they probably had partial breast and head plating for protection against spears, missiles etc.

Under the successors of Alexander

The Companion cavalry of the Diadochoi (Alexandrian successor-states), were all more heavily equipped. Seleucid Companions were noted to have worn lighter, but not otherwise dissimilar, equipment to the cataphracts at the Battle of Magnesia in 190 BC, which may have included partial horse armour and leg and arm protection. Ptolemaic Companions were also equipped with a large round aspis 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 of Companions was kept as a regimental title. 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.