While the rest of the world eagerly awaits the final season of HBO’s “Game of Thrones,” one of the show’s key stars will debut a new project that’s very close to his heart.

The network has announced the premiere date of “Gunpowder,” starring Kit Harington.

In partnership with BBC One, HBO will debut the three-part thriller based on the events in the 17th century that led to Guy Fawkes Day. In addition to starring, Harington will co-executive produce the show.

The reason the star is taking such a commanding role in this project is simple: it’s a family thing.

The star is a descendant of Robert Catesby, the central figure of the series and mastermind behind the infamously foiled gunpowder plot. He’s also who the Jon Snow actor will be playing.

“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.”

Catesby was a driving force behind the 1605 plot in London to kill James I. The series will depict a time when Catholics were persecuted by Protestant England. Catesby’s refusal to abandon his religion brings him “to the edge of financial, social and psychological ruin” as he navigates a shadow game involving spies and a government dedicated to hunting him, his family and priests down to torture and kill them.

The new series will debut on December 18 and play out over the next two nights, ending on December 20.