“Look to the sky. Doom and ruin surround us,” says Ser Criston Cole (Fabien Frankel) as the war intensifies in season three of HBO’s Game of Thrones prequel, House of the Dragon.

‍House of the Dragon tells the story, as laid out in George R. R. Martin’s Fire and Blood, of how House Targaryen divided against itself in a great civil war. Set 200 years before Game of Thrones, which is celebrating the 15th year since the global hit premiered, it reminds audiences that the Targaryens were always questionable rulers whose defining feature was access to powerful dragons who could destroy armies and cities from the air. 

In the trailer, James Norton is revealed as the religious Lord Ormund Hightower, a significant new player in the conflict, cousin to the Queen Mother, Alicent Hightower (Olivia Cooke), and leader of the Hightower army. Alicent’s sons – King Aegon II (Tom Glynn-Carney) and Prince Regent Aemond (Ewan Mitchell) – are at each other’s throats after Aegon recovers from disastrous wounds and the power-hungry Aemond takes over. 

“I’m going to kill my brother, or die in the attempt,” the now-scarred Aegon (Tom Glynn-Carney) says.

In the meantime, Princess Rhaenyra (Emma D’Arcy) and Prince Daemon Targaryen (Matt Smith) continue to fight for the throne they believe is theirs. 

“There will be no doubt who the gods have chosen to rule,” Rhaenyra says as she dangles her crown in front of her.

The trailer also features plenty of fire, blood and dragons, as to be expected from a show about Targaryens. House of the Dragon is the second of three HBO series set in the fictional realm of Westeros: Game of Thrones, House of the Dragon and A Knight of the Seven Kingdoms, which aired its first season earlier this year.

‍House of the Dragon is executive produced by co-creator and showrunner Ryan Condal, co-creator Martin, Sara Hess, Melissa Bernstein, Kevin de la Noy, Vince Gerardis, David Hancock and Philippa Goslett.  

‍House of the Dragon premieres its third season on Sunday, June 21, at 9 p.m. ET/PT on HBO and will be available to stream on HBO Max. The season includes eight episodes with the season finale airing on Sunday, August 9.