The reason they were enemies is because of the war that Poseidon started.
Poseidon's greatest enemy was his father, Cronus.
Some of Athena's rivals are Medusa, Aphrodite, and Poseidon.
Zeus is Poseidon's enemy and brother.
Poseidon
Hades, Poseidon and Adamas. Adamas was the 13th god and we all know before that there were only 12 olympians,
athena is his enemy
Yes
Odysseus blinded Poseidon's son Polyphemus.Odysseus did not consider Poseidon his enemy, as it would be foolhardy for a mortal to be an enemy to any god. However, Poseidon was a wrathful god who was punishing Odysseus for blinding his son, the cyclops Polyphemus, by piercing his only eye. As a result, Poseidon hampered Odysseus' efforts to get home, giving him trials.Eventually Odysseus builds a shrine to Poseidon to appease the god, although the actual event is takes place after the events in the Odyssey.Poseidon is not a traditional enemy, in the normal sense of 'enemy'.
His rival is Athena.But probably his enemy is Oceanus, the titan of the sea.
Poseidon was Athena's enemy:(
Poseidon
Trojan warriors