The Minotaur was a monstrous hybrid of man and bull, entrapped within the Labyrinth - a maze created by Daedalus for the King of Crete, Minos.
It is said that, every nine years, a selection of fourteen Athenian youths (seven men and seven women) were sent into the Labyrinth as mortal offerings to the Minotaur. Theseus, son of the then ruler of Attica, infiltrated the Labyrinth as part of this sacrificial mass - determined to slay the beast and prevent further suffering.
Apparently, Labyrinth overseer - the daughter of Minos - Ariadne fell in love with Theseus on first sight. She gave him a ball of thread, to be unravelled behind him as he walked; to leave the Labyrinth, he need simply trace the line.
Killing the Minotaur proved an easy task, and with the help of Ariadne's thread Theseus escaped back to Athens.