One prequel to the hit fantasy series Game of Thrones has already been announced in the form of House of the Dragon, which will detail the complicated and bloody history of the Targaryen family. Now, HBO has been revealed to be working on a second prequel, this one inspired by George R. R. Martin’s three-novella series “Tales of Dunk & Egg.”

Set nearly one hundred years before the events of Game of Thrones, Tales of Dunk and Egg tells of the journeys of wandering hedge knight, Ser Duncan “Dunk” the Tall, and his squire “Egg,” who is eventually revealed to be Prince Aegon Targaryen. The series currently consists of three novellas, The Hedge Knight, The Sworn Sword, and The Mystery Knight, which were later collected in one volume as A Knight of the Seven Kingdoms. Graphic novel versions of The Hedge Knight and The Sworn Sword have also been released.

Although series author George R. R. Martin previously planned to write a number of additional novellas starring Dunk and Egg, possibly totaling as many as nine, this never came to pass as he chose instead to focus on The Winds of Winter. Later books in the Song of Ice and Fire series and some references in Game of Thrones confirm that Egg eventually became King Aegon V the Unlikely, while Ser Duncan served in his Kingsguard. It is possible that an HBO series might move beyond the scope of the books and cover later events in the two men’s lives, much as Game of Thrones itself did in its final seasons.

Currently, no names have been attached to the project, although it is reportedly a high priority for HBO. The series is planned to feature one-hour episodes. No release date is known, but it would likely debut sometime after House of the Dragon, which is currently planned for sometime in 2022 barring further COVID-19-related delays.