When did Theseus father die?

Theseus' father, King Aegeus of Athens, died when Theseus returned from Crete after slaying the Minotaur. Aegeus had instructed Theseus to raise white sails on his ship if he was successful, but when he saw the black sails instead, believing his son had died, he jumped into the sea in despair. This event is said to have occurred in ancient Greek mythology rather than a specific historical date.