Held at Mt. Olympus, there was a wedding where all the god and goddesses were invited, except one was accidentally left off. Her name was Eris.
Eris wanted revenge so she invited herself to the after party and appeared with a golden apple amongst the quest. Three goddesses claimed the apple.
Paris was chosen by Hermes to pick a goddess. He picked Aphrodite and she gave him the most gorgeous wife named Helen, who was the wife of the Greek king.
Paris took Aphrodite's promise and visited Helen. He seduced and abducted her back to Troy. The Greeks were angry and unified in power to find Troy. The Greeks then traveled for 10 years looking for Troy.
Finally, Odysseus came up with the idea to build a large wooden horse to store men in. They left the horse at Troy's gate. The Trojans took the horse into the city and the Greeks jumped out and defeated the Trojans to win the war.