The hetairoi, 'companions', were the mounted nobility of Macedon, bound to the king by a personal relationship that the name states plainly. They were heavy cavalry by ancient standards: armoured, riding without stirrups, and armed with the xyston, a stout thrusting lance used overarm.
Their tactical signature was the wedge, which the tradition attributes to Philip and which allowed a compact body to enter a gap and widen it. The Companions did not charge formed infantry frontally; in every one of Alexander's battles they are directed at a seam that has opened or been induced to open.
Riding without stirrups constrains what heavy cavalry can do, and the point is often misunderstood. A rider secured by a deep saddle and by thigh grip could deliver a lance thrust effectively; what he could not do is absorb the shock of a couched-lance charge in the medieval manner.
What the evidence supports
The Companions were the decisive arm in Alexander's battles.
At the Granicus, Issus and Gaugamela the break is made by the Companion charge led by Alexander in person.
The wedge formation is attributed to Philip.
Reported in the Hellenistic tactical writers, who also credit Scythian and Thracian precedent.
Stirrups were not in use.
Stirrups reach the Mediterranean world far later. Ancient heavy cavalry was effective without them, which is a fact about riding technique rather than a limitation on effectiveness.
Primary sources
Arrian, Anabasis of Alexander 1.14-16, 2.10-11, 3.13-15
The Companion charges at the three great battles.
Asclepiodotus, Tactica
On cavalry formations including the wedge.
Battles
338 BCE
Chaeronea
Philip II defeated the combined armies of Athens and Thebes, ending the independence of the Greek city-states as a system of competing powers.
334 BCE
The Granicus
Alexander's first battle in Asia, fought at a river crossing against the satraps of the western provinces, and the engagement that opened Asia Minor to him.
333 BCE
Issus
Alexander's first battle against Darius III, fought on a narrow coastal plain that neutralised Persian numbers, and after which the Persian royal family fell into Macedonian hands.
331 BCE
Gaugamela
The decisive battle of the Persian war, fought on ground Darius had chosen and prepared, and after which the Achaemenid empire had no field army left.
How to read the evidence labels
- Evidence level: Documented
- Supported by a named primary text or by excavated material evidence.
- Evidence level: Probable
- Supported by strong inference that most specialists accept.
- Evidence level: Disputed
- Substantial specialist disagreement exists; competing readings are stated.
- Evidence level: Literary
- Belongs to poetic or mythological construction rather than to history.
- Evidence level: Mythological
- Belongs to shared religious or mythic tradition rather than to any single text.
- Evidence level: Unknown
- The available evidence is insufficient to decide.
These labels describe the status of the evidence, not our confidence in a conclusion. A claim marked Literary is not a claim we doubt; it is a claim about what kind of thing a poem is.