Introduction
Aethra was the daughter of King Pittheus of Troezen. She bore Theseus after a night in which, by different tellings, she lay with the visiting Aegeus, with Poseidon, or with both.
Family
Guardian of the Tokens
Aethra raised Theseus in Troezen, and when he came of age she showed him the boulder under which Aegeus had hidden a sword and sandals, sending him to Athens to claim his birthright. Late in her life she was abducted by the Dioscuri in retaliation for Theseus's earlier abduction of their sister Helen, and served as a captive attendant to Helen during the Trojan War.
As with all figures of Greek heroic legend, sources diverge on many particulars; the account above follows the most widely transmitted classical tradition.