The first trailer for HBO's upcoming Game of Thrones prequel, House of the Dragon, has been published. The prequel series, based on George R.R. Martin's book Fire Blood, follows House Targaryen nearly two centuries before the War of the Five Kings, which would follow the House's loss of the Iron Throne.

According to the official HBO synopsis, "The Targaryen dynasty is at the pinnacle of its power in the prequel series, with more than 15 dragons under their control. Most empires, both actual and imagined, disintegrate when they reach such heights. The Targaryens' long descent begins about 193 years before the events of Game of Thrones, when King Viserys Targaryen defies a century of tradition by naming his daughter Rhaenyra as the Iron Throne's heir. However, when Viserys has a son, the court is taken aback when Rhaenyra preserves her status as his heir, sowing seeds of dissension throughout the realm."

House of the Dragon has received a 10-episode straight-to-series order from HBO. With Martin and Vince Gerardis, Miguel Sapochnik and Ryan Condal will serve as co-showrunners and executive producers. The series is expected to premiere in 2022, according to HBO. In April, production began.

The new prequel series, one of several in development, is co-created by Game of Thrones creator George R.R. Martin and Condal and is based on Martin's book Fire Blood. Paddy Considine, Matt Smith, Steve Toussaint, Rhys Ifans, Eve Best, Sonoya Mizuno, and Fabien Frankel are among the cast members.