How did the war start and end?
The war basically war begun after the abduction of Queen Helen of Sparta by the Trojan prince Paris. Helen's jilted husband Menelaus convinced his brother Agamemnon, king of Mycenae, to lead an expedition to retrieve her (history.com). The Trojan War ended when the Greeks defeated Troy using a large wooden horse. The hollow wooden horse helped the Greeks gain entry inside the walls of Troy (reference.com).
Who were the major players in the war?
The major players in the Trojan War are (about.com):