If it hadn't been for Poseidon, Theseus would never have been the leading hero of Athens; Jason would have been short-staffed; and Hercules would have had fewer labors. Still, if you're looking for lots of violent confrontations between mortal heroes and the trident wielder, you'll be disappointed. Most of Poseidon's work in the legends was done before the heroes were born.
"'Be glad, woman, in our love, and as the year goes on its course thou shalt bear glorious children, for not weak are the embraces [250] of a god. These do thou tend and rear. But now go to thy house, and hold thy peace, and tell no man; but know that I am Poseidon, the shaker of the earth.'
Odyssey 11.249f
That's not to say Poseidon didn't shake things up a bit.
Poseidon, Theseus and the Minotaur
Pasiphae was Queen of Crete, married to Minos, but enamored of the snow-white bull Poseidon had given her husband. Unable to restrain herself, Pasiphae prevailed upon the renowned craftsman Daedalus to construct a device by which she could fool the bull into thinking her a cow. Her plan worked; the outcome of the union between Pasiphae and the bull was a creature with a human body, but taurine head and tail. This bull-man was the Minotaur.
Before you go pitying her husband, thinking, "Poor cuckolded Minos," let me assure you that Minos was not the innocent victim of divine wrath. Poseidon had deluded the queen to punish her husband Minos' sacrilege, for King Minos had reneged on his promise to sacrifice the perfect bull to the sea god, Poseidon.
Minos was, despite his guilt, unhappy with the monster his wife had produced as half-brother to their daughters Ariadne and Phaedra, and sons Demophon and Acamas. Minos commissioned the same crafty Daedalus to construct a labyrinthine prison for the creature whose appetites ran to a yearly tribute of 14 young men and women from Athens.
Poseidon and Theseus
While the Minotaur wasn't actually an offspring of Poseidon, his nemesis, Theseus, probably was. Theseus' mortal step-father was the Athenian king Aegeus and his mother, Aethra. Unfortunately for the sake of positive identification, it appears the queen slept with both lovers on the same night, so the paternity is in doubt.
Theseus was one of the 7 youths and 7 maidens selected by the Athenians for the annual tribute and monster feast. Some say he volunteered in order to show his prowess. At any rate, Theseus was attractive enough to win the hearts of both the daughters of King Minos. Given the advantage of Ariadne's help -- the equivalent of a ball of string -- Theseus found his way into the center of the labyrinth and back out again following his meeting and pulverizing the Minotaur [Apollod. Epit. E.1.9].
Also see: Carlos Parada's Minotaur Page.Poseidon and Phaedra
The youthful Theseus wowed the older daughter of King Minos but fell in love with his younger daughter.
Because of an unsatisfactory dalliance with Poseidon, the goddess of love did not favor Theseus. So, when Theseus' son further insulted her by honoring not her but Artemis and on Cyprus, at that, Aphrodite sought revenge.
Theseus' son, Hippolytus had been born to the Amazon, Antiope, but she died. When Theseus married Phaedra, Hippolytus joined them. Aphrodite's revenge was to make Phaedra fall madly in love with her step-son -- with devastating, if predictable, consequences. In the end, according to Euripides, Theseus prevailed upon his father to send a bull from the sea to kill the unlucky Hippolytus.
Poseidon - The Lesser Share Part 2 continuesTheseus
Bullfinch's story of the adventures of the semi-historical Theseus.Euripides' Hippolytus
E. P. Coleridge's translation of the ultimate woman-scored drama, from Internet Classics Archive
