Patroclus is a son of Menoetius. While only a boy, he accidentally killed another boy over a game of dice. He and his father were forced to flee their home. They fled to Phthia, where they were accepted by the king Peleus. In Phthia, Patroclus met Peleus' son Achilles, and the two became lovers. When Achilles was forced to go fight against Troy, Menoetius sent Patroclus with him.
In the Trojan War, Patroclus presumably fought alongside Achilles. When Achilles lost Briseis to Agamemnon, and refused to fight, Patroclus and the other Myrmidons loitered near the ships with him.
When it appear that the Greeks might lose the war, Patroclus approached Achilles with an idea. He asked Achilles if he could wear his armor, and lead the Myrmidons against the Trojans. Achilles agreed. All went well for a while. The Trojans fled, thinking Achilles had returned to battle. Eventually, however, Patroclus is killed by Hector, who takes his armor.
After his death, Achilles holds huge games. Twelve Trojan captives are killed in combat. Athletic competitions are held, with handsome prizes for the winners.