Matthew Rhydder, who played Jon Snow in the HBO series “Game of Hearts,” died Monday after battling a rare form of throat cancer, his agent told The Associated Press.

Rhys was 55.

He was diagnosed with throat cancer in December 2014 and was treated at a New York hospital.

His agent, David Farrar, said in a statement that the actor died of natural causes.

Rhydthers family was not immediately available for comment.

Rhyder is survived by his wife of 11 years, actress Katie O’Donnell, and their three children, aged 1, 4 and 6.

The actor was nominated for an Emmy for his work in the second season of the HBO drama, which premiered in October.

His character is played by actor Gwendoline Christie, who won an Emmy in 2016 for her portrayal of Sansa Stark on the HBO show.