‘House of the Dragon’ Is Coming. Here’s What You Need to Know.

In the final episodes of HBO’s “Game of Thrones,” the mad queen Daenerys Targaryen incinerated most of the capital city of King’s Landing. But what was it like when it was all still standing, and the Targaryen dynasty ruled with an iron fist — er, throne?

That’s the question explored by “House of the Dragon,” the new series set in author George R.R. Martin’s revisionist epic-fantasy world. Created by Martin along with Ryan Condal, who serves as showrunner with the veteran “Thrones” director Miguel Sapochnik, “Dragon” takes place far back into the ancestral line of the “Thrones” protagonists Daenerys and Jon Snow, whose own Targaryen identity was revealed late in the original show’s run.

As their forebears battle for control of Westeros’s Iron Throne, what do you need to know about the new series, and its connection to what has gone before — or, more accurately, after? Our cheat sheet has you covered. Read on and prepare to dance with dragons.

A pregame of thrones

Though it is the successor series to “Game of Thrones,” “House of the Dragon” is actually a prequel. Set 172 years before the birth of Daenerys Targaryen, it chronicles the history of her royal family during a tumultuous time, a calamitous internecine war known as “The Dance of the Dragons.” During this conflict, a slew of Targaryens and their dragon steeds — these fire-breathing beasts were more plentiful at this point in Westerosi history — did battle for the Iron Throne.

That said, “Dragon” shares several key elements with its predecessor series. These include Martin, who wrote the books that form the basis of both shows — the “A Song of Ice and Fire” novels for the original series and the prequel book “Fire & Blood” for the new one.

Condal is new to the franchise, as is the entire cast. But Sapochnik, the other showrunner, directed several of the most memorable “Thrones” episodes, including “Hardhome,” “Battle of the Bastards” and “The Bells.” The composer Ramin Djawadi returns, as do unmistakable elements of his “Thrones” theme music.

In addition, the setting of King’s Landing and its royal seat, the Red Keep, are virtually identical to the versions we’ve seen previously, as are the various noble houses’ symbols or “sigils” and even their hairstyles. The Iron Throne itself may have been enhanced by hundreds more melted-down blades, but this is very much the same Westeros we’ve already occupied for eight seasons.

A family affair

“Game of Thrones” famously depicted strife between several noble houses, most notably the Starks and the Lannisters, who rose to power after the death of the last Targaryen monarch, the Mad King Aegon IV. But most of these houses — Stark, Lannister, Greyjoy, Tyrell, Martell — recede into the background in “House of the Dragon.” The new show is focused almost exclusively on the Targaryen family, the dynasty that conquered Westeros over a century before the events that kick off “Dragon.”

When the series begins, a great council of the aristocracy is convened to select Old King Jaehaerys Targaryen’s son Viserys (Paddy Considine) over his older female cousin, Rhaenys (Eve Best), as heir to the throne, on explicitly patriarchal grounds. The council, a comparatively democratic body during these feudal times, is intended to put such questions of succession to rest.

In Westeros, as in our world, momentous decisions often reverberate in unexpected directions and lead to unanticipated conflict. The main players in “House of the Dragon” include the well-meaning but ineffectual King Viserys and his younger brother, the roguish Prince Daemon (Matt Smith), who would inherit the throne if his brother dies. Viserys’s closest adviser is Otto Hightower (Rhys Ifans), the Hand of the King — a position of great influence, as it was in “Thrones.” Hightower is a rival of the kingdoms’ richest man, the veteran seafarer Corlys Velaryon (Steve Toussaint), who is married to Rhaenys and who, like the Targaryens, is a descendant of the ancient empire of Valyria.

In an echo of the earlier succession dispute, another natural claimant to the throne is Viserys’s daughter, Princess Rhaenyra (Milly Alcock as a youth, Emma D’Arcy as an adult), his only surviving child. Also central to things is Rhaenyra’s childhood friend Alicent Hightower (played by Emily Carey and Olivia Cooke), the daughter of the ambitious and calculating Otto.

Trouble, obviously, ensues.

Unreliable narrators

“Game of Thrones” was based on Martin’s “A Song of Ice and Fire” novels: “A Game of Thrones,” “A Clash of Kings,” “A Storm of Swords,” “A Feast for Crows” and “A Dance With Dragons.” (Still to come: “The Winds of Winter,” which Martin has been working on for years, and “A Dream of Spring.”) But “Fire & Blood,” the “Dragon” source material, is written as a faux-historical tome rather than as a proper novel. Martin wrote the book in the voice of one Archmaester Gyldayn, a historian from within the world of Westeros itself. As such, many of its main characters’ motives, actions and dialogue remain matters of conjecture.

Complicating matters further, Gyldayn’s primary and secondary sources have their own conflicting writing styles, political loyalties and points of view. (Among the fandom, the most popular of these is “The Testimony of Mushroom,” a salacious account of events written by the Targaryen court jester, who does not seem to appear in “Dragon” at all, at least not yet.) These shifting viewpoints leave several crucial matters, from trysts to betrayals, in a did-they-or-didn’t-they limbo.

Given that several of these question marks drive the battles for supremacy that will likely drive “Dragon” in turn, the show will have to come down on one side or the other. For longtime fans and newcomers alike, these are likely to be the juiciest and most thrilling sections of the story, which will unfold over multiple seasons, if the gods be good.

Light your candles to the Seven, and we’ll learn together who comes out on top.