Pleistarchus

[2] Pleistarchus was born as a prince, likely the only son of King Leonidas I and Queen Gorgo.

[3] He was born from an avunculate marriage – his parents were uncle and niece.

[5] Pleistarchus' father King Leonidas perished in 480 BC at the Battle of Thermopylae.

For the early part of Pleistarchus's reign, his uncle Cleombrotus acted as regent; after Cleombrotus's death in 479 BC, Pleistarchus's cousin Pausanias was regent.

[7] He had no known surviving relatives after his death, marking the end of his bloodline.