Although we might know him as the young Prince Phillip in Netflix's 'The Crown', Matt Smith will be playing royalty once again in HBO's prequel series of 'Game of Thrones'.

It's been announced that a total of three new cast members are joining 'House of the Dragon', alongside the previously-announced Paddy Considine. As well as Smith joining the cast, two other actors are also along with him - Olivia Cooke and Emma D'Arcy.

Cooke previously starred in 'Bates Motel' and is currently starring in the Irish-set comedy thriller 'Pixie', where she plays the lead role. Emma D'Arcy, meanwhile, previously starred in Prime Video's TV spinoff of 'Hanna', and the horror-comedy series 'Truthseekers' opposite Nick Frost and Malcolm McDowell.

Smith will play Prince Daemon Targaryen, Paddy Considine's on-screen younger brother, and is described as "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..."

Meanwhile, Cooke and D'Arcy will play Alicent Hightower and Rhaenyra Targaryen respectively. Hightower is described as "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."

Meanwhile, Rhaenyra is described as "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."

So far, no confirmed release date has been set for 'House of the Dragon', but it's expected to be at least 2022 before it hits screens, as production is due to begin at some stage in the new year.