Demosthenes The Funeral Speech 30

[30] It did not escape the Oeneidae that Semele was the daughter of Cadmus, and of her was born one whom it would be sacrilegious to name at this tomb, ¹ and by him Oeneus was begotten, who was called the founder of their race. ² Since the danger in question was common to both States, on behalf of both they thought themselves bound to endure any Anguish to the end. ³ The Cecropidae were well aware that their founder was reputed to have been part dragon, part human, for no other reason than this, that in understanding he was like a man, in strength like a dragon. So they assumed that their duty was to perform feats worthy of both.