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
Ancient Macedonian army and leather shields used by peltasts) that already diverged from the "hoplon" style shield featured in sculpted artwork of a Katerini tomb, dated perhaps to the reign of Amyntas III of Macedon. His early infantry were also equipped with protective helmets and greaves, as well as "sarissa" pikes, yet according to Sekunda they were eventually equipped with heavier armour such as cuirasses, since the "Third Philippic" of Demosthenes in 341 BC described them as hoplites instead of lighter peltasts. As evidenced by the Alexander Sarcophagus, troops serving Alexander the Great were also armoured in the hoplite fashion. However, Errington argues