Gangaridai (
Gangaridae) was an ancient state, which existed around 300 BC, in the
Bengal region of the
Indian Subcontinent. It was described by the Greek traveller
Megasthenes in his work
Indica. Greek and Latin historians suggested that
Alexander the Great withdrew from the Indian Subcontinent, anticipating the valiant joint counterattack of the mighty Gangaridai and Prasii (
Nanda) Empires, the latter located in central
Bihar. The capital of the Gangaridais is believed to be situated at Kotalipara.