Ajax (ˈeɪdʒæks) or Aias (ˈaɪ.əs; Aíās aí̯.aːs, () Αἴαντος Aíantos; archaic ΑΣϜΑϺ aí̯.waːs) is a Greek mythological hero, the son of King Telamon and Periboea, and the half-brother of Teucer. He plays an important role in the Trojan War, and is portrayed as a towering figure and a warrior of great courage in Homer's Iliad and in the Epic Cycle, a series of epic poems about the Trojan War, being second only to Achilles among Greek heroes of the war. He is also referred to as "Telamonian Ajax" (Αἴας ὁ Τελαμώνιος, in Etruscan recorded as Aivas Tlamunus), "Greater Ajax", or "Ajax the Great", which distinguishes him from Ajax, son of Oileus, also known as Ajax the Lesser.
Ajax is the son of Telamon, who was the son of Aeacus and grandson of Zeus, and his first wife Periboea. Through his uncle Peleus (Telamon's brother), he is the cousin of Achilles, and is the elder half-brother of Teucer.
The etymology of his given name is uncertain. By folk etymology his name was said to come from the root of aiazō αἰάζω "to lament", translating to "one who laments; mourner". Hesiod provided a different folk etymology in a story in his "The Great Eoiae", where Ajax receives his name when Heracles prays to Zeus that a son might be born to Telemon and Eriboea: Zeus sends an eagle (aetos αετός) as a sign, and Heracles then bids the parents call their son Ajax after the eagle.
Many illustrious Athenians, including Cimon, Miltiades, Alcibiades and the historian Thucydides, traced their descent from Ajax. On an Etruscan tomb dedicated to Racvi Satlnei in Bologna (5th century BC) there is an inscription that says aivastelmunsl, which means "[family] of Telamonian Ajax".
In the account of Dares the Phrygian, Ajax was illustrated as ". . .powerful. His voice was clear, his hair black and curly. He was perfectly single-minded and unrelenting in the onslaught of battle." Meanwhile, In Homer's Iliad he is described as of great stature, colossal frame, and strongest of all the Achaeans.