'A Knight of the Seven Kingdoms,' the newest 'Game of Thrones' prequel, is on the horizon. Here's what to know about it.

• HBO is expanding the "Game of Thrones" universe with another prequel series.
• "A Knight of the Seven Kingdoms" takes place between the main series and "House of the Dragon."
• It's based on George R. R. Martin's novellas that follow a hedge knight, Dunk, and his squire, Egg.

"House of the Dragon" season three probably won't air until the summer of 2026, but "Game of Thrones" fans have another prequel to look forward to in the meantime: "A Knight of the Seven Kingdoms."

Although the "Game of Thrones" ending disappointed many fans in 2019, HBO recognized the world of Westeros as a lucrative property. And there's plenty of material to use, considering all the spinoff stories and novellas that George R. R. Martin has written.

The network is also working on other "GoT" prequel shows, including "Nine Voyages," "Ten Thousand Ships," and "The Golden Empire."

"A Knight of the Seven Kingdoms" is set about 70 years after "House of the Dragon" and 100 years before "Game of Thrones," as the network fills in the huge timeline of the fantasy franchise. The series will premiere on January 18, 2026, with each of its six episodes airing weekly thereafter.

The story follows Dunk, aka Ser Duncan the Tall, and his squire, Egg. Here's what you need to know about "A Knight of the Seven Kingdoms."

'A Knight of the Seven Kingdoms' plot follows Dunk and Egg

The first season is based on Martin's first novella in the "Tales of Dunk and Egg" series, titled "The Hedge Knight" (1998).

It introduces Dunk, an orphan from Flea Bottom, who dubs himself Ser Duncan the Tall. The young man is what's known in Westeros as a hedge knight; instead of pledging fealty to any particular lord, he roams around the country, offering his services and protecting the innocent.

The novella opens with the death of Dunk's mentor, Ser Arlan of Pennytree. Left to his own devices, Dunk decides to enter a tournament at Ashford Meadow to make a name for himself (and hopefully make some money). On the way, he meets a 9-year-old boy with a shaved head, who introduces himself as Egg and offers to serve as Dunk's squire.

After "The Hedge Knight," the unlikely duo's adventures continue in "The Sworn Sword" (2003) and "The Mystery Knight" (2010).

In May 2023, HBO executive Francesca Orsi told Deadline that the network plans to adapt each of the three novellas into a six-episode season. "A Knight of the Seven Kingdoms" has already been renewed for season two, set to debut in 2027.

Fans who are familiar with "Game of Thrones" lore know that Dunk and Egg go on to play significant roles in Westerosi history — but as with the source material for "Game of Thrones," the full story has not yet been put to page.

In a 2015 blog post, Martin said he plans to write more installments in the Dunk and Egg series, ideally spanning the entire lives of these characters. He said tentative titles include "The She-Wolves of Winterfell," "The Village Hero," "The Sellsword," "The Champion," "The Kingsguard," and "The Lord Commander."

Should Martin release these in the future, HBO could easily turn "A Knight of the Seven Kingdoms" into a longer-running series.

The cast is led by Peter Claffey and Dexter Sol Ansell

"A Knight of the Seven Kingdoms" stars former rugby player Peter Claffey ("Bad Sisters") as Dunk, and Dexter Sol Ansell ("The Hunger Games: The Ballad of Songbirds & Snakes") as Egg.

Claffey is in his late 20s, meaning that his character has been aged up for the screen; in Martin's original novella, Dunk is still a teenager when Ser Arlan dies. Meanwhile, Ansell was 9 years old while filming season one, the same age as Egg.

Showrunner Ira Parker told Business Insider that he hopes to minimize the time off between filming each season because Ansell is "a ticking time bomb of cuteness."

"That relationship between him and Dunk is really lovely," Parker said. "We'd like to get as many in as we can before things start getting a little precarious around 12, 13."

While the show is predominantly focused on Dunk and other common folk in his orbit, there are several secondary characters with familiar surnames — ancestors of characters we see in "Game of Thrones."

Claffey and Ansell are joined in the season one cast by Bertie Cavel ("The Crown") as Baelor Targaryen, heir to the Iron Throne; Sam Spruell ("Fargo") as Baelor's brother, Maekar Targaryen; Henry Ashton ("A Good Girl's Guide to Murder") as Maekar's eldest son, Prince Daeron Targaryen; Finn Bennett ("True Detective: Night Country") as Maekar's second son, Prince Aerion Targaryen; and Daniel Ings ("The Gentlemen") as Ser Lyonel Baratheon.

Additionally, Tanzyn Crawford will play Dunk's love interest, Tanselle. Ser Arlan is portrayed in flashbacks by Danny Webb.

The trailers tease both violence and humor

"Ser Arlan raised me to be a true knight," Dunk says in the official trailer, "not with sword or lance, but with honor."

Clips include glimpses of knights jousting and swordfighting, as well as several cheeky digs at Dunk's appearance. The steward of Ashford (Tom Vaughan-Lawlor) tells Dunk that he's dressed more like a farmer, while a woman describes his role as being "like a knight, but sadder."

Even Egg gets in on the ribbing: "Every knight needs a squire, and you look like you need one more than most."

The trailer also foreshadows tension between the common folk and the royal family. At this point in Westerosi history, the Targaryens are still in charge, but their dragons have died out, significantly weakening their claim to power. In one clip, Raymun Fossoway (Shaun Thomas) describes the Targaryens as "incestuous aliens and tyrants."

There's a particular beef apparently brewing between Dunk and Aerion, referred to in the "Fire and Blood" history book as Aerion the Monstrous — a big enough threat that Dunk is advised to flee for his own safety.

"Won't they kill me if I run?" Dunk wonders aloud.

"Won't they kill you anyway?" Raymun replies.

Eammon Jacobs and Palmer Haasch contributed to an earlier version of this story.