Theseus was known for his triumph over numerous monsters, especially the Minotaur, which lived in a labyrinth on the island of Crete. Every year the people of Athens had been forced to send fourteen young people for the Minotaur to eat alive. But Theseus, using a ball of magic thread from the princess Ariadne, found his way in and out of the labyrinth and killed the beast. Theseus was the son of either Aegeus, king of Athens, or the sea god Poseidon. In later life he became king of Athens and a famous warrior.