Pittheus was the son of Pelops in Greek mythology, who later became the king of the region of Troezen. His daughters were Aethra and Henioche. King Aegeus of Athens visited the court of Pittheus to ask him what he understood of a prophecy he had received from an oracle. He had asked the oracle if he would ever father any children. Pittheus got Aegeus drunk, who then had intercourse with Aethra; on that same night, Aethra had also laid with the god Poseidon. She was impregnated to Theseus, and thus, Aegeus became the stepfather of the mythical hero. Theseus was raised in the court of Pittheus.
A few years later, Heracles visited Pittheus, having completed the famous Labours of Heracles. During his visit, he left his lion-skin cape on a couch. At that point, the seven-year-old Theseus arrived home with his friends, who upon seeing the lion-skin, thought it was alive, and fled. Theseus, however, took an axe and attacked it.
After Theseus grew up and became the king of Athens, he married Phaedra and had a son, Hippolytus. Hippolytus visited his grandfather Pittheus and stayed with him, in order to be raised for the throne of Troezen.