According the Greek myth, King Minos prayed to Poseidon to send him a white bull to show that King Minos not only had the god's favor, but also the right to rule. Poseidon granted King Minos' wish on the condition that the king would sacrifice the bull in honor of Poseidon. King Minos did not honor this deal, wanting to keep the bull for himself. This white bull became known as the Cretan Bull.
As punishment, Poseidon caused Queen Pasiphaë, the king's wife, to fall in love with the bull. She ordered a craftsman to create a wooden cow for her to hide inside and mate with the white bull. The result of this unholy union was the Minotaur, a creature with the head of a bull and body of a man. Pasiphaë cared for her child, but he grew into a monster that ate humans to survive, save for his mother.
Fearing the child, King Minos went to the Oracle of Delphi, who told the king he needed to create a large labyrinth to house the Minotaur and Pasiphaë, who went made within the maze-like walls. King Minos had the large structure built near his palace in Knossos. The king was to send sacrifices to the Minotaur, or the beast would destroy the kingdom. These sacrifices were men that had been captured in wars, many being Athenians.
When the third sacrifice was to occur, Theseus went to slay the Minotaur. He told his father, Aegeus, that he would use white sails to show that he was successful, and the crew would use black sails if Theseus died. It was said that Ariadne, daughter of King Minos, fell in love with Theseus and gave him a ball of thread so that he could find his way out of the labyrinth. Using the sword of Aegeus, Theseus slew the beast and lead the sacrifices out of the labyrinth safely. Though Ariadne traveled back to Athens with Theseus, he abandoned her on the island of Naxos as he did not love her nor wanted her along. Theseus also forgot to put up the white sails to inform his father of his victory. King Aegeus saw the black sails as he looked out on Cape Sounion. The heart broken king committed suicide by throwing himself into the Aegean Sea. This allowed Theseus to take over the throne of Athens.