The Minotaur

Before he ascended the throne of Crete, Minos struggled with his brothers for the right to rule. Minos prayed to Poseidon to send him a snow-white bull, as a sign of approval by the gods for his reign. He promised to sacrifice the bull as an offering, and as a symbol of subservience. A beautiful white bull rose from the sea, but when Minos saw it, he coveted it for himself. He assumed that Poseidon would not mind, so he kept it and sacrificed the best specimen from his herd instead. When Poseidon learned about the deceit, he made Pasipha, Minos' wife, fall madly in love with the bull. She had Daedalus, the famous architect, make a wooden cow for her. Pasipha climbed into the decoy and fooled the white bull. The offspring of their lovemaking was a monster called the Minotaur.
The creature had the head and tail of a bull on the body of a man. It caused such terror and destruction on Crete that Daedalus was summoned again, but this time by Minos himself. He ordered the architect to build a gigantic, intricate labyrinth from which escape would be impossible. The Minotaur was captured and locked in the labyrinth. Every year for nine years, seven youths and maidens came as tribute from Athens. These young people were also locked in the labyrinth for the Minotaur to feast upon.

When the Greek hero Theseus reached Athens, he learned of the Minotaur and the sacrifices, and wanted to end this. He volunteered to go to Crete as one of the victims. Upon his arrival in Crete, he met Ariadne, Minos's daughter, who fell in love with him. She promised she would provide the means to escape from the maze if he agreed to marry her. When Theseus did, she gave him a simple ball of thread, which he was to fasten close to the entrance of the maze. He made his way through the maze, while unwinding the thread, and he stumbled upon the sleeping Minotaur. He beat it to death and led the others back to the entrance by following the thread.