The oldest source providing information about the city of Trabzon and the surrounding area is Xenophon's “Anabasis”. In this work Xenophon describes how, after the death of his father, Dareios, Ataxerxes II rebelled against his brother, who was then emperor of Persia. He set out with an army of mercenaries from Sardes (Salihli) and encountered the army of the emperor at Kunaksa, near the Babylon of Kyros, governor of Western Anatolia.