He was sent out as harmost in 400 BC, with an army of about 5,000 men, composed of 1,000 Neodamodes (emancipated helots) and 4,000 other Peleponesians, to aid the Ionians against Tissaphernes, who wished to bring them into subjection.
In addition to this force, Thibron recruited 2,000 local troops upon his arrival, but was initially unable to face the Persian army in the field.
He then, according to Xenophon, settled in to besiege Larissa, but this proved fruitless, and Thibron was ordered to abandon it.
[5] In 391 BC, during the Corinthian War, Thibron was again dispatched to Ionia with orders to take aggressive action against the Persian satrap Struthas, who was pursuing a pro-Athenian, anti-Spartan policy.
Struthas successfully lured Thibron and his men into ideal cavalry terrain before launching the attack.