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
Thracian language by ancient sources considered explicitly of Thracian origin and known meaning An additional 180 Thracian words have been reconstructed. The proposed Thracian words in the Ancient Greek lexicon are not numerous. They include the "parth-" element in Parthenon; "balios" ("dappled"; < PIE "*bhel-", "to shine", Bul. "bel/bial" (бял) "white" or "bljaskav" 'bright, shiny'; Pokorny also cites Illyrian as a possible source, the non-Greek origin is argued on phonological grounds), "bounos", "hill, mound". The Thracian horseman hero was an important figure in Thracian religion, mythology, and culture. Depictions of the Thracian Horseman are found in numerous archaeological remains and artifacts from