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
Cyrus the Younger his expedition. By dexterous management and large promises, he overcame the misgivings of the Greek troops over the length and danger of the war; a Spartan fleet of thirty-five triremes sent to Cilicia opened the passes of the Amanus into Syria and conveyed to him a Spartan detachment of 700 men under Cheirisophus. The king had only been warned at the last moment by Tissaphernes and gathered an army in haste; Cyrus advanced into Babylonia before he met with an enemy. In October 401 BC, the battle of Cunaxa ensued. Cyrus had 10,400 Greek hoplites (citizen-soldiers), 2,500 peltasts (light infantry),