Achilles tending Patroclus' wounds from about 490-500 B.C. The painter is Euphronios, and the work is regarded as his masterpiece. In Greek mythology, Achilles was a Greek hero of the Trojan War, the central character and the greatest warrior of Homer's Iliad. Legends state that Achilles was invulnerable in all of his body except for his heel. He died because of a small wound on his heel, thus the term Achilles' heel has come to mean a person's principal weakness. Patroclus was the son of Menoetius, grandson of Actor, King of Opus, and was Achilles' beloved comrade and brother-in-arms. The exact nature of Achilles' relationship with Patroclus has been a subject of dispute in both the classical period and modern times.