According to the oracle, the wrath of Poseidon could only be appeased by the sacrifice of one of the king's daughters.
Otus and Ephialtes, in ancient Greek legend, the twin-sons of Poseidon by Iphimedeia, wife of Aloeus.
Leto escapes to Ortygia, which Poseidon covers with the sea in order to protect Leto.
The story ran that both Zeus and Poseidon had sought her hand, but, Themis (or Prometheus or Proteus) having warned the former that a son of Thetis by Zeus would prove mightier than his father, the gods decided to marry her to Peleus.
Another tradition makes him a giant of the sea, ruler of the fabulous Aegaea in Euboea, an enemy of Poseidon and the inventor of warships (Schol.
It is said that Pallas, Hephaestus, and Poseidon entered into a competition as to which of them could create the most useful thing.
The sacredness of the horse to Poseidon, the epithets Hippios and Equester applied to Poseidon and Neptune, the Greek fable of the origin of the first horse (produced by Poseidon striking the ground with his trident), and the custom in Argolis of sacrificing horses to Poseidon by drowning them in a well.
According to Suidas he composed a number of songs and proems; none of these is extant; the fragment of a hymn to Poseidon attributed to him (Aelian, Hist.An.xii.45) is spurious and was probably written in Attica in the time of Euripides.
This adventure was even more ignominious than that of Poseidon and Apollo when they were compelled to serve Laomedon for hire.
It contained the ancient image of Athena Polias, and three altars, one to Poseidon and Erechtheus, one to Butes and one to Hephaestus; there were portraits of the family of the Butadae on the walls.