Ygraine: Your father betrayed me. He went to the sorceress Nimueh and asked for her help in conceiving a child. You were born of magic.
Arthur: That's not true!
Ygraine: I'm sorry, Arthur. Your father has deceived you, as he deceived me. To create a life, a life must be taken. Your father knew that.
Ygraine: He sacrificed my life so the Pendragon dynasty could continue. It makes you no less my son, nor me any less proud of you. Now I see you, I would have given my life willingly. Do not let this knowledge change you.