Ian Gelder, who is best known for his role as Kevan Lannister on the HBO hit “Game of Thrones,” has passed away at the age of 74.

“It is with huge huge sadness and a heavy heart broken into a million pieces that I’m leaving this post to announce the passing of my darling husband and life partner Ian Gelder,” Gelder’s husband and fellow actor Ben Daniels wrote in an Instagram post.

Gelder had been diagnosed with bile duct cancer in December. “He was the kindest, most generous spirited and loving human being,” Daniels wrote.

Over the course of an acting career that spanned decades, Gelder appeared in a number of movies and television shows, including “Torchwood” and “Doctor Who.” His biggest role came in the late 2010’s, however, when he was cast as Kevan Lannister in the first season of “Game of Thrones.”

Gelder in the fifth season of the HBO classic “Game of Thrones”

Gelder appeared in a handful of episodes in the first season and was upgraded to the main cast in the show’s fifth season, when he took over as “hand of the king” and effectively ruled the show’s fictional kingdom. He ultimately appeared in four of the show’s eight seasons.

Gelder was also a veteran stage actor, playing major roles including Antonio in “The Merchant of Venice” and the Duke of Clarence in “Richard III” at the Royal Shakespeare Company (RSC), CNN reported.