Poseidon had bestowed upon him a magic golden hair on his head, which made him immortal and unconquerable so long as the hair grew. Pterelaus and his kin raided the cattle of the King of Mycenae. He was then killed in a retaliatory expedition led by Amphitryon after being betrayed by Comaetho, who had fallen in love with Amphitryon and pulled out the golden hair on her fathers' head, which rendered him defenseless. The vanquished Taphian realm was handed over to Amphitryon's allies, including Cephalus. Cephalus ruled over many islands, and his followers became known as Cephallenians.