Doctor Who and The Crown alum Smith will play Prince Daemon Targaryen, described as the "younger brother to King Viserys and heir to the throne. A peerless warrior and a dragonrider, Daemon possesses the true blood of the dragon." Ready Player One star Cooke will take on the role of Alicent Hightower, "the daughter of Otto Hightower, the Hand of the King, and the most comely woman in the Seven Kingdoms. She was raised in the Red Keep, close to the king and his innermost circle; she possesses both a courtly grace and a keen political acumen." Truth Seekers star D'Arcy will play Princess Rhaenyra Targaryen, "the king’s first-born child, she is of pure Valyrian blood, and she is a dragonrider. Many would say that Rhaenyra was born with everything… but she was not born a man." According to EW, "Rhaenyra is considered a major rock star role within the show."