 Tyro exposed her sons on a mountain to die, but they were found by a herdsman who raised them as his own, as one story goes, or they were raised by a maid.When they reached adulthood, Pelias and Neleus found Tyro and killed her stepmother Sidero for having mistreated her (Sidero hid in a temple dedicated to Hera but Pelias killed her anyway, causing Hera's undying hatred of Pelias).Pelias was power-hungry and he wished to gain dominion over all of Thessaly.