Leonidas (Greek: "Lion's son", "Lion-like") was a king of Sparta, the 17th of the Agiad line, one of the sons of King Anaxandridas II of Sparta, who was believed to be a descendant of Heracles. Leonidas was one of three: he had an older brother Dorieus and a younger brother Cleombrotus, who ruled as regent for a while on Leonidas death before being taken over as regent by Pausanias who was Cleombrotus son. He succeeded his half-brother Cleomenes I, probably in 489 or 488 BC, and was married to Cleomenes' daughter, Gorgo. His name was raised to heroic status as a result of the events in the Battle of Thermopylae.