Dec. 12 (UPI) -- Doctor Who and The Crown actor Matt Smith has joined the cast of the Game of Thrones prequel, House of the Dragon.
HBO said Friday that Smith will play Prince Daemon Targaryen.
"The younger brother of King Viserys and heir to the throne, Daemon is a peerless warrior and a dragonrider who 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," the cable network said in a news release.
Other new cast additions include Ready Player One actress Olivia Cooke and Truth Seekers star Emma D'Arcy. They join the previously announced series lead Paddy Considine, who will play King Viserys Targaryen.
The show is based on George R.R. Martin's fantasy novel Fire & Blood. It takes place 300 years before the events of Game of Thrones.
HBO's Emmy-winning adaptation of Game of Thrones aired for eight seasons from 2011 to 2019.
No premiere date has been announced for the prequel.