Aethra
Αἴθρα
The princess of Troezen who met both a king and a sea god in one night, and bore Theseus.
Daughter of Pittheus, king of Troezen, she is said to have lain with both Aegeus and Poseidon on the same night. That is why Theseus is called both a king's son and a sea god's son.
Aegeus hid a sword and sandals under a rock before he left, and Aethra revealed the secret once her son grew strong enough to lift it.
Later she was carried off to Troy as Helen's handmaid, and freed by her grandsons after the war. The old woman standing beside Helen on the walls in the Iliad is her.
SourcesApollodorus, Library