Kit Harington is staying in the HBO family.

The Emmy-nominated Game of Thrones actor will star in a new miniseries for the pay cabler that will debut this December. Gunpowder, set in the 17th century about the build-up to Guy Fawkes Day, is a three-part thriller that also features Peter Mullan, Mark Gatiss, and Liv Tyler in main roles. Ronan Bennett is the credited writer, while J Blakeson (The Disappearance of Alice Creed) helmed the production.

The project is a personal one for Harington: He’s a descendent of Robert Catesby, the central figure in the story who he is set to play. A committed Catholic at a time when Protestant England persecutes Catholics relentlessly, Catesby’s refusal to abandon his religion brings him to the edge of financial, social, and psychological ruin in the series. Gatiss plays Robert Cecil, King James’ spymaster, who directs efforts to hunt down, torture, and kill priests, while rank-and-file Catholics are subject to oppression and the loss of their property. Harington is also a co-executive producer on Gunpowder.

“We are delighted to offer a platform for a project that is so close to Kit Harington’s heart,” Kary Antholis, president of HBO Miniseries and Cinemax Programming, said in a statement. “Kit’s passion for and belief in Gunpowder are evident in every frame of the miniseries.”

Added Harington, “Three years ago, Daniel West and I conceived and began developing Gunpowder with Kudos and Ronan Bennett. We are now thrilled to share this unique story with the U.S. audience. I can’t think of a better place to do that than my home at HBO.”