Patroclus of Phthia, son of Menoetius and Sthenele, is renowned as tbe close friend of Achilles in the Iliad. Patroclus accompanied Achilles to the Trojan War. As a suitor of Helen, Patroclus would have been obliged by the oath of the suitors (Oath of Tyndareus) to go to Troy, even if he hadn't gone as Achilles' friend. Patroclus brought 10 ships to the Achaean fleet.
When Achilles refused to fight, Patroclus begged him to let him wear his armor, and so, dressed as Achilles, but without the hero's valor, Patroclus was unevenly matched when he fought Hector, and so, he died. Menelaus recovered the corpse of Patroclus.
Because Hector killed Patroclus, Achilles was enraged and re-joined the battle to get his revenge. Achilles killed Hector and then desecrated his corpse, by dragging it around by the belt Hector had received as a gift from Ajax.
Carlos Parada Patroclus