King Peleus and the goddess Thetis were getting married, and everybody was invited. Everybody that is except Eris, the goddess of discord. In true storybook-villain fashion, she had a hissy fit and got her revenge by throwing a golden apple amongst the guests announcing that it was a gift for the most beautiful amongst them.
Of course all the goddesses started squabbling about who should have it, and the wedding celebrations were quickly forgotten. The “competition” was soon whittled down to three finalists: Hera (wife of Zeus and queen of the gods), Athena (goddess of wisdom), and Aphrodite (goddess of love).
Unable to decide amongst themselves they agreed to ask Paris, a Trojan prince, to be the judge. Desperate to win, each of the three goddesses offer gifts to Paris to tempt him to choose her. Hera said she would make him the king of the whole of Europe; Athena offered to make in the most skilful warrior the world had ever seen; and Aphrodite promised him the hand of her sister Helen – the most beautiful woman in the world – in marriage.
Not stopping to consider that by naming one goddess the winner he would be making enemies for life of the other two, Paris immediately proclaimed Aphrodite the most beautiful goddess, and he claimed Helen as his own prize.
Unfortunately Helen was already married to Menelaus, King of Sparta, who vowed to get his wife back, and thus the Trojan War was begun.