He was a son of Saulius, the brother and slayer of Anacharsis. When Darius I of Persia invaded Scythia, about 513 BC, and the Scythians retreated before him, he sent a message to Idanthyrsus, calling upon him either to fight or submit. The Scythian king answered that, in fleeing before the Persians, he was not urged by fear, but was merely living the wandering/nomadic life to which he was accustomed, that there was no reason why he should fight the Persians, as he had neither cities for them to take nor lands.