The god Poseidon sent a white bull to Crete by request of King Minos. The Bull was supposed to be sacrificed, but King Minos changed his mind and let it live.
Pasiphae, the king's wife fell in love with the white bull. She visited him at night and they, mated. This resulted in Queen Pasiphae giving birth to a Minotaur. It was supposed to be a secret, but Daedalus, the king's architect, charmed by the beauty of the king's daughter, Phaedra, revealed the secret of the Minotaur.
She got interested and decided to visit the Minotaur one night.
When the giant bull saw Phaedra, he got so excited that he ran through the thick wall of the labyrinth.
Phaedra jumped up on his back and they fled to Atlantis, where they mated and gave birth to a Unicorn.
For those who are not too prudish, here is Picasso's version of it. (scroll down about 40% of the page.)
video clips here, the music is by me!
clip 1: Fred at Knossos Palace, 2004 (includes a Greek guide tour)
clip 2: Real artifacts from Knossos Palace
clip 3: documentary filmed in the ancient Roman town, Gortyn. (voice over by my wife, Louisa.)