He was an Argonaut, and was, along with most of his twenty sons, killed in Heracles' war against Hippocoon, king of Sparta.
[2] Cepheus was a member of the Arcadian royal family, the descendants of Pelasgos, the first king of Arcadia.
[14] Pausanias also mentions two other daughters of Cepheus, Aerope, who died giving birth to a son of the god Ares,[15] and Antinoe.
[19] The hero Heracles sought the help of Cepheus and his twenty sons, in his campaign against Hippocoon, king of Sparta.
But, according to Apollodorus, Cepheus did not want to leave his kingdom unprotected, fearful that if he did, the Argives would march against Tegea.