Battle of Gaugamela main Persian infantry was poorly trained and equipped in comparison to Alexander's pezhetairoi and hoplites. The only respectable infantry Darius had were his 2,000 Greek hoplites and his personal bodyguard, the 10,000 Immortals. The Greek mercenaries fought in a phalanx, armed not with a heavy shield but with spears no longer than three metres, while the spears of the Immortals were two metres long. Among the other Persian troops, the most heavily armed were the Armenians, who were armed the Greek way and probably fought as a phalanx. The rest of Darius' contingents were much more lightly armed; the main
Thracians without women and were called "ktisti". In myth Orpheus became attracted to men after the death of Eurydice and is thought of as the establisher of homosexuality among Thracian men. Because he advocated love between men and turning away from loving women he was killed by the Bistones women. The Thracians were a warrior people, known as both horsemen and lightly armed skirmishers with javelins. Thracian peltasts had a notable influence in Ancient Greece. The history of Thracian warfare spans from c. 10th century BC up to the 1st century AD in the region defined by Ancient Greek and Latin