Why did Pittheus trick Aegeus? The story of Theseus' birth has already been covered in this forum. My question is about Pittheus' _motivation_ behind getting Aegeus drunk and offering him his daughter Aethra. In Euripedes' _Medea_ , Aegeus describes Pittheus as 'closest of all my allies'. So why did Pittheus, who understood the Pythia's prophesy, deliberately trick Aegeus into not following the prophesy and thus cause Aegeus' death (albeit quite some time later)? What did Pittheus have to gain by this? Influence in Athens?

A grandson.

Since his purpose was to get him to sleep with his daughter, he must have deduced that the resulting son would be something special, and special enough to risk angering Aegeus.

At least, on the face of it. There are no myths that go into what he was thinking.