The Game of Thrones franchise is about to return with its first-ever spinoff, House of the Dragon. Here’s everything to know about the prequel before its premiere: 

When is ‘House of the Dragon’ set? 

House of the Dragon takes place about 200 years before the events in Game of Thrones, and it focuses on the Dance of the Dragons, a civil war among the Targaryens over who has the rightful claim to the throne. 

When Game of Thrones begins, Robert Baratheon is king, having succeeded a Targaryen: King Aerys II Targaryen, the “mad king” who was murdered by Jaime Lannister. This prequel flashes back many years before that, to another time when the Targaryens ruled. King Viserys I Targaryen sits on the Iron Throne after succeeding his grandfather, King Jaehaerys Targaryen. Before his death, Jaehaerys assembled a huge council of the lords of Westeros in Harrenhal to determine who should succeed him, and they picked Viserys, who officially took over a few years later. 

“Many consider the reign of King Viserys I to represent the apex of Targaryen power in Westeros,” according to George R.R. Martin’s Fire & Blood, which notes that during this time, “there were more dragons than ever before.” That’s as opposed to the Game of Thrones era, in which dragons are believed to be extinct when the series begins and very few Targaryens are still alive — mainly Daenerys, her brother Viserys, and Jon Snow, who’s later revealed to have Targaryen lineage. House of the Dragon also picks up in a time of relative peace for Westeros. 

“This period in Westeros was a very decadent time,” showrunner Ryan J. Condal noted. “So you get to see what the realm looks like before it descends into the detritus and post-decadence of war that you see in the original series.” 

What’s the source material? 

Like Game of Thrones, House of the Dragon is based on George R.R. Martin’s writing, in this case 2018’s Fire & Blood, which reads like an in-universe history book about the Targaryens rather than a novel. Because it’s mostly just a summary of events, the show has plenty of wiggle room to fill in details, even if the basic plot is already known to book readers. 

What’s it about?

Think of the hook of House of the Dragon as being, essentially, “Succession, but with dragons.” 

As the show’s trailer outlines, King Viserys (Paddy Considine) in season one is called upon to officially name his heir, raising questions as to whether it will be his brother, Prince Daemon Targaryen (Matt Smith), or daughter, Princess Rhaenyra Targaryen (Emma D’Arcy). “I will not be made to choose between my brother and my daughter,” Viserys says in the trailer. Rhaenyra has constantly been at the king’s side since when she was a child, and she is described in Fire & Blood as the “great joy” of his life.

There is, though, one big problem with her claim to the throne: As described in Fire & Blood, the great council that picked Viserys as king established “in the eyes of many” a precedent that “regardless of seniority, the Iron Throne of Westeros could not pass to a woman.” According to this precedent, if the king has no first-born son, his brother comes before his daughter in the line of succession. Indeed, Rhaenyra is told in the trailer that “a woman would not inherit the Iron Throne because that is the order of things.” 

Fire & Blood describes Daemon, who sees himself as Viserys’ rightful heir, as “ambitious, impetuous, moody,” and “as charming as he was hot-tempered,” while Rhaenyra is described as “cherished and adored by all” when she was a child. She even earns the nickname of “the Realm’s Delight.” Milly Alcock, who plays young Rhaenyra, in an interview with Entertainment Weekly, compared her to Arya Stark. “There is that rebellious and cheeky spirit that they both possess, which I think is why people are going to adore her,” Alcock said. 

Who are the other characters? 

The cast also includes Rhys Ifans as Ser Otto Hightower, the Hand of the King, and Fire & Blood describes how Otto strongly dislikes Prince Daemon and feels Rhaenyra should sit on the Iron Throne instead. “Time and time again,” the book says, “[Viserys] strove to make peace between Prince Daemon and Ser Otto.”

Olivia Cooke plays Otto’s daughter, Alicent Hightower. She was best friends with Rhaenyra since they were children, but eventually marries Rhaenyra’s father, King Viserys. Then there’s Steve Toussaint playing Lord Corlys Velaryon, a rich “nautical adventurer” known as the Sea Snake. His family, the Velaryons, have long been the “oldest and closest allies of the Targaryans,” Fire & Blood notes. 

Eve Best plays Corlys Velaryon’s wife, Princess Rhaenys Targaryen. She’s a dragonrider who’s nicknamed “The Queen Who Never Was” because she was passed over for the throne when Viserys was chosen to be King Jaehaerys’ heir during that big Harrenhal council. “The realm favored her cousin, Viserys, simply for being male,” HBO’s character description notes. 

There’s also Tom Glynn-Carney as Aegon Targaryen, who will become a crucial player in the Dance of the Dragons as the show progresses, though the reason why is a bit of a spoiler. 

Unlike Game of Thrones, House of the Dragon will jump forward many years during the course of the series. According to The Hollywood Reporter, a 10-year time jump occurs midway through the first season, at which point Olivia Cooke and Emma D’Arcy take over the roles of Alicent and Rhaenyra from younger actresses. Because this is a period when dragons were plentiful, the show will also feature a whopping 17 of them. 

Who are the writers and producers?

Game of Thrones creators David Benioff and D. B. Weiss have no involvement in this series. Instead, House of the Dragon was co-created by Ryan J. Condal and author George R. R. Martin himself. Miguel Sapochnik, who directed some of Thrones‘ most acclaimed episodes like “Battle of the Bastards,” serves as producer, and Ramin Djawadi, who composed the original series’ iconic theme, is back writing the music. 

When does it premiere?

House of the Dragon premieres Aug. 21 on HBO, and the first season’s 10 episodes will air weekly. If it’s a hit, it should be followed by multiple additional Thrones spinoffs, one of which is expected to be a sequel about Jon Snow. 

The plan is for House of the Dragon‘s main civil war storyline to last only “three or four seasons,” though the show could potentially continue after that by telling more stories from Targaryen history, according to The Hollywood Reporter. But let’s not get ahead of ourselves: For now, a second season of House of the Dragon hasn’t officially been ordered.