“Needling one another and in the middle of it is Paddy, who plays Viserys.”
He told Empire: “They’re both vying for his attention and his love.”
As the House of the Dragon is a prequel none of the original stars from Game of Throne will make an appearance.
Also joining the cast are Olivia Cooke, Graham McTavish and Eve Best.
House of the Dragon will premiere in the US on HBO on Sunday, August 21, and then on Monday, August 22, on Sky Atlantic and NOW TV in the UK