Leonidas I (/liːˈɒnɨdəs/ lee-ON-i-dəs or /liːˈɒn.ɨ.dæs/; Doric and Modern Greek: Λεωνίδας [leɔːnídas], Leōnidas; Ionic Greek: Λεωνίδης, Leōnidēs; "son of the lion"; died 480 BC), also known as Leonidas the Brave was a Greek hero-king of Sparta, the 17th of the Agiad line, third son of Anaxandridas II of Sparta,[2] who was believed to be a descendant of Heracles, possessing much of the latter's strength and bravery. Leonidas is notable for his leadership at the Battle of Thermopylae.