Theseus is best known for offering himself as one of the Athenian youths sent to the Cretan King Minos to become the monstrous, bull-headed, half-human Minotaur's dinner. Minos' step-son, the Minotaur, lived in a labyrinth built by Daedalus (of Icarus fame). Getting through the labyrinth without help was impossible, so simply being put in the labyrinth practically guaranteed the Athenian youth would die. However, King Minos must have done something wrong. He might have paraded the latest Minotaur-meal before his subjects. At any rate, at least one of Minos' daughters, Ariadne, fell in love with the vision of heroic manliness that was Theseus. She found a way to give him a ball of yarn, while Theseus waited, perhaps in a cell, for his turn in the labyrinth. With the ball of yarn leading to and from the door at the labyrinth entrance, Theseus knew he would be able to find his way out again, so with his bare hands he set about capturing the Minotaur. Alternatively, Theseus killed Ariadne's half-brother with a sword Ariadne must also have supplied. Ovid puts a club in Theseus' hands.
In return for her favor, Theseus took Ariadne away with him to marry her, but en route, he ditched her. This was the same trip on which Theseus forgot to change the colors of his sails, the result of which was the suicide of his father.