The other major House of the Dragon cast members are:
- Olivia Cooke as Alicent Hightower, who is "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."
Cooke told Metro.UK that Alicent is "very different" from her recent role in the movie Pixie, whom she described as "really manipulative and conniving and selfish." Perhaps Alicent is one of the good eggs in this world.
- Matt Smith as Prince Daemon Targaryen, described as "younger brother to King Viserys and heir to the throne. A peerless warrior and a dragonrider, Daemon possesses the true blood of the dragon. But it is said that whenever a Targaryen is born, the gods toss a coin in the air…"
- Emma D’Arcy as 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."
In February, four more cast members were announced:
- Steve Toussaint as Lord Corlys Velaryon aka "The Sea Snake," who will be the lord of House Velaryon. Their bloodline is old as House Targaryen, and Velaryon earned his nickname for being the most notorious "nautical adventurer in the history of Westeros."
- Eve Best as Princess Rhaenys Velaryon, a dragonrider who is wife to Lord Corlys Velaryon. She did not get the throne at the Great Council because — hold your surprise — "the realm favored her cousin, Viserys, simply for being male."
- Rhys Ifans as Otto Hightower. As Hand of the King, Hightower is protecting the throne loyally, and sees the king's brother Daemon (Matt Smith) as the biggest threat to the monach.
- Sonoya Mizuno as Mysaria. Mysaria had nothing when she arrived in Westeros. Now, after she's "sold more times than she can recall," she's actually got the trust and of Daemon, the heir to the throne.
- Fabien Frankel as Ser Criston Cole, a member of King Viserys I Targaryen's Kingsguard. On his blog, George R.R. Martin wrote Ser Criston is "the common-born son of the steward to the Lord of Blackhaven. He has no claim to lands or titles, all he has is his honor and his skill with sword and lance. He is a challenger, a champion, cheered by the commons, beloved of the ladies. He is a lover (or is he?), a seducer (or is he?), a betrayer (or is he?), a breaker of hearts and a maker of kings