King Eurystheus ordered Heracles to capture the Cretan Bull and bring it to him as part of his seventh labor. Prince Minos sought a sign from Poseidon to confirm his right to rule Crete.
But although the hero himself is lacking a head, there is a different head lying at his feet — that of the Cretan Bull, the creature that Pasiphaë fell in love and sired the Minotaur with.