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
Slavic speakers of Greek Macedonia Greek Macedonia 24 chetas and 10 local reconnaissance detachments were active. Many locals were repressed by the Greek authorities on suspicions of contacts with the revolutionary movement. In this period the combined Macedonian-Adrianopolitan revolutionary movement separated into Internal Thracian Revolutionary Organization and Internal Macedonian Revolutionary Organization. ITRO was a revolutionary organization active in the Greek regions of Thrace and Eastern Macedonia to the river Strymon. The reason for the establishment of ITRO was the transfer of the region from Bulgaria to Greece in May 1920. At the end of 1922, the Greek government started to expel large numbers of Thracian