Battle of Gaugamela
According to Herodotus, the 'Indians' participated to the Second Persian invasion of Greece circa 480 BCE. At the final Battle of Platea (479 BCE), they formed one of the main corps of Achaemenid troops (one of "the greatest of the nations"). Indians were still supplying troops and elephants for the Achaemenid army at the Battle of Gaugamela (331 BCE). They are also depicted on the Achaemenid tombs of Naqsh-e Rostam and Persepolis.