Dune, The Witcher star joins new Game of Thrones prequel show as Leo Tyrell

The second season of House of the Dragon is over and we likely won't see season 3 until sometime in 2026. But we will get to revisit Westeros before that. Next year, HBO will debut a new Game of Thrones prequel series called A Knight of the Seven Kingdoms, based on the Tales of Dunk and Egg novellas by George R.R. Martin.

A Knight of the Seven Kingdoms is an altogether smaller story than we saw in either Game of Thrones or House of the Dragon. There's no massive war afoot (or at least, Martin hasn't written the novellas where things get that big); there's just a very tall knight named Ser Duncan the Tall and his diminuitive squire Egg, who wander the Seven Kingdoms having adventures. The first season will be based on Martin's story "The Hedge Knight," which begins with Dunk entering himself into a tournament in Ashford Meadow in the Reach. There he'll meet a variety of characters, including a member of the Tyrell family: Leo "Lornhorn" Tyrell, regarded as one of the best knights House Tyrell ever produced.

Leo is steadfast, an excellent jouster, and well-liked. According to Redanian Intelligence, he'll be played by Steve Wall, who's also appeared in shows and movies like Vikings, Raised by Wolves, Dune: Part Two and The Witcher, where he played Boholt in the first season. Now he'll play the first member of House Tyrell fans have seen since Lady Olenna Tyrell met her end in the seventh season of Game of Thrones.

The Tyrells are rulers of the Reach, so it makes sense that at least one of them would show up in a tournament held in that part of the Seven Kingdoms. Wall joins a pretty comprehensive cast. Check out who we know is in the show thus far:

• Peter Claffey as Ser Duncan the Tall, aka Dunk, the good-hearted hero of our story
• Dexter Sol Ansell as Egg, Dunk's squire
• Danny Webb as Ser Arlan of Pennytree, an elderly knight and Dunk's master
• Finn Bennett as Aerion "Brightflame" Targaryen, a half-mad Targaryen prince
• Bertie Carvel as Baelor "Breakspear" Targaryen, Aerion's more level-headed uncle
• Sam Spruell as Maekar Targaryen, Aerion's father
• Tanzyn Crawford as Tanselle, a puppeteer
• Daniel Ings as Lyonel Baratheon, who participates in the tourney
• Edward Ashley as Ser Steffon Fossoway
• Shaun Thomas (How to Have Sex) as Raymun Fossoway
• Youssef Kerkour (House of Gucci) as Steely Pate
• Daniel Monks (Kaos) as Ser Manfred Dondarrion
• Tom Vaughan-Lawlor (Avengers: Infinity War) as Plummer
• Ross Anderson as Humfrey Hardyng
• Steven Calvert as a Stormland knight
• Rowan Robinson as Rowan
• Abigail O'Regan in an unknown role

Redanian Intelligence also brings us the news that Nina Jamil has joined the crew of A Knight of the Seven Kingdoms as an intimacy coordinator, including there will be at least one sex scene. We'll find out for sure when the show premieres on HBO and Max sometime next year. Exact release date to come.

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