Poseidon, the Greek god of the sea, was one of the twelve Olympian gods in Greek mythology. According to Greek mythology, Poseidon had many children, both mortal and immortal, but his most well-known son was the hero Theseus.
Theseus was the son of Poseidon and Aethra, a mortal woman. According to legend, when Aethra was pregnant with Theseus, she was visited by both Poseidon and Aegeus, the king of Athens. Each god told her that her child would become great, but she was unsure which god was the true father of her child.
To ensure that Theseus would be raised as a hero, both Poseidon and Aegeus gave Aethra gifts that would aid in his upbringing. Poseidon gave Aethra a magical sword that would only be revealed to Theseus when he was ready to claim his birthright as a hero, while Aegeus left a pair of sandals and a sword hidden under a rock for Theseus to claim when he was strong enough.
As Theseus grew older, he proved himself to be a brave and skilled warrior, and he eventually became one of the greatest heroes of Greek mythology. He was known for his many adventures, including slaying the Minotaur, a monster with the body of a man and the head of a bull that lived in the Labyrinth on the island of Crete.
In addition to Theseus, Poseidon had many other children in Greek mythology. Some of his most famous offspring include Polyphemus, the Cyclops that Odysseus encountered on his journey home from the Trojan War; Orion, a great hunter and constellation in the night sky; and Triton, a merman and the messenger of the sea.
Overall, while Poseidon had many children in Greek mythology, his most well-known son was Theseus, the hero who proved himself worthy of his divine heritage and became one of the greatest heroes of all time.