Theseus and Aethra, by Laurent de La Hyre
Aegeus, one of the primordial kings of Athens, found a bride, Aethra who was the daughter of king Pittheus at Troezen, a small city southwest of Athens. On their wedding night, Aethra waded through the sea to the island of Sphairia that rests close to the coast and lay there with Poseidon (god of the sea and earthquakes). The mix gave Theseus a combination of divine as well as mortal characteristics in his nature; such double fathers, one immortal and one mortal, was a familiar feature of Greek heroes.[5] After Aethra became pregnant, Aegeus decided to return to Athens. Before leaving, however, he buried his sandals and sword under a huge rock[6] and told Aethra that when their son grew up, he should move the rock, if he were heroic enough, and take the tokens for himself as evidence of his royal parentage. In Athens, Aegeus was joined by Medea, who had left Corinth after slaughtering the children she had born, and had taken Aegeus as her new consort. Priestess and consort together represented the old order in Athens.
Thus Theseus was raised in his mother's land. When Theseus grew up and became a brave young man, he moved the rock and recovered his father's tokens. His mother then told him the truth about his father's identity and that he must take the sword and sandals back to king Aegeus to claim his birthright. To journey to Athens, Theseus could choose to go by sea (which was the safe way) or by land, following a dangerous path around the Saronic Gulf, where he would encounter a string of six entrances to the Underworld,[7] each guarded by a chthonic enemy. Young, brave, and ambitious, Theseus decided to go alone by the land route and defeated a great many bandits along the way.
The Six Entrances of the Underworld
• At the first site, which was Epidaurus, sacred to Apollo and the healer Asclepius, Theseus turned the tables on the chthonic bandit, the "clubber" Periphetes,