In the spring of 479 BC, following the death of his co-ruler Leonidas at the Battle of Thermopylae, Leotychidas commanded a Greek fleet consisting of 110 ships at Aegina and later at Delos, supporting the Greek revolts at Chios and Samos against Persia. Leotychidas defeated Persian military and naval forces at the Battle of Mycale on the coast of Asia Minor in the summer of 479 BC (possibly around mid-August). In 476 BC, Leotychidas led an expedition to Thessaly against the Aleuadae family for collaboration with the Persians but withdrew after being bribed by the family. Upon returning to Sparta he was tried for bribery, and fled to the temple of Athena Alea in Tegea. He was sentenced to exile and his house burned. He was succeeded by his grandson, Archidamus II, son of his son Zeuxidamus, called Cyniscus, who had died in his father's lifetime. Leotychidas died some years later, around 469 BC.