The Trojan War began when the Trojan Prince Paris kidnapped Helen, the wife of Menelaus, king of Sparta. He was assisted by Aphrodite, who had promised him Helen, the most beautiful woman in the world, as a reward for siding with her in a competition against the goddesses Hera and Athena.
The competition began when Eris, goddess of discord, threw a golden apple into the wedding of the sea goddess Thetis with the inscription, "for the fairest." Hera, Athena, and Aphrodite all claimed the apple for themselves. Zeus decided that Paris, the most beautiful man on Earth, should be the judge. The three goddesses each offered him a reward for siding with her. Hera offered him power. Athena offered him wealth. Aphrodite offered him Helen. After Paris kidnapped Helen, Menelaus called all of Helen's former suitors, who had all promised to defend her honor, to attack Troy and rescue her.