British actor Fabien Frankel (The Serpent, NYPD Blue) has joined the cast of House of the Dragon, the upcoming Game of Thrones prequel series, according to Deadline. Frankel will play Ser Criston Cole, a "common-born son of the steward to the Lord of Blackhaven… all he has to his name is his honor and his preternatural skill with a sword."

Frankel is part of a cast that includes Doctor Who actor Matt Smith as Daemon Targaryen, Paddy Considine as King Viserys Targaryen, Olivia Cooke as Alicent Hightower, and Emma D'Arcy as Princess Rhaenyra Targaryen. It's been rumored that the series will have five lead characters, so it's possible these actors will fill those roles.

House of the Dragon is co-created by author George R.R. Martin and Ryan Condal (Colony, Rampage). Miguel Sapochnik (Trainspotting, Game of Thrones) will serve as showrunner along with Condal. Joining them as a writer and executive producer will be Sara Lee Hess (Orange is the New Black, Deadwood).