the war was fought between the kingdom's of troy and mycenaean greece, the trojan war started because the trojan prince paris abducted helen, wife of menelaus, the king of sparta. menelaus persuaded his brother agamemnon to form an alliance of greek cities to sail to troy and retrieve helen. the war lasted 10 years, the trojans were defeated after the greeks left behind a large wooden horse and pretended to sail for home. unbeknown to the trojans, the wooden horse was filled with greek warriors.