J.J. Murphy, the veteran stage actor who had worked alongside Liam Neeson and Ciaran Hinds at the Lyric Theatre in his native Belfast, has passed away at the age of 86.

The Northern Irish actor had recently booked the role of Ser Denys Mallister of the Night’s Watch on Season Five of HBO’s Game of Thrones. But after Murphy completed his scheduled scenes this past Friday, he collapsed and was later pronounced dead. He had not been on set at the time.

The tragedy comes only four days into filming and Murphy was due to appear in more scenes, however, showrunners David Benioff and D.B.Weiss do not intend to recast the role. They are satisfied with the footage they were able to get from his brief time before the cameras.

“We will not be recasting J.J. Murphy,” said Benioff and Weiss in a statement. “He was a lovely man, and the best Denys Mallister we could have hoped for. And now his watch is ended.”

Murphy’s character, Ser Denys Mallister, plays a prominent role in the storyline of Jon Snow. He is the oldest member of the Night’s Watch and one of the leading candidates to take over the position of Lord Commander after the murder of Jeor Mormont, the previous Lord Commander of the Watch.

Though not a household name, J.J. Murphy appeared in film and television with roles in films such as 1999’s Angela’s Ashes, based upon the Frank McCourt autobiography and most recently the upcoming Dracula Untold starring Luke Evans and Dominic Cooper.

He was also actively involved in advocating for the union rights of Irish actors and his efforts won him an honorary lifetime membership with the former British Actors’ Equity Association, now known simply as Equity.

Murphy leaves behind a wife, Mary, and two grown children, Joseph and Jane.