Neil Fingleton, the British actor and basketball player who has also officially been Britain’s tallest man since 2007, has died at age 36.

Best known for his role as Mag the Mighty, the giant character in HBO’s hit fantasy drama series “Game of Thrones,” which is months from entering its seventh and penultimate season, Fingleton also appeared in “X-Men” prequel/reboot “X-Men: First Class,” which revolutionised and revitalised the whole franchise, and the 2013 martial arts fantasy movie “47 Ronin,” starring Keanu Reeves in a role that harps back to his apparent Asian roots in a less effective way than his later, more successful, more iconic kung fu movie-inspired role in the “John Wick” franchise.

Cause of death is as yet unconfirmed

Fingleton’s cause of death has yet to be confirmed by the representative who announced that he had passed, however, some reports are coming in that it was heart failure. The behemoth actor, who was just shy of 7 feet and 8 inches tall and weighed 370 lb, must’ve taken some maintenance from his organs and immune system to keep him ticking away.

The Tall Persons Club posted on social media their grief over the passing of Britain’s tallest man. They posted earlier today, “Sadly it has come to our attention that Neil Fingleton...passed away on Saturday.” The organisation sent out their “thoughts and condolences” to Fingleton’s family and loved ones.

Fingleton hails from Durham and was born in 1980.

He completed his high school and college education in America and while he wasn’t drafted by the NBA, he did play in the ABA in the 2004-2005 season in a team called the Boston Frenzy. He also played professional basketball across Europe in Italy, Spain, and Greece.

Named tallest man by Guinness Book of World Records

The Guinness Book of World Records published in 2007 named the tallest man in Britain, and after that, Fingleton switched from a basketball career to an acting one, which was very successful, taking roles in such films and Television shows as “Avengers: Age of Ultron,” “Doctor Who,” “Jupiter Ascending,” and yes, “Game of Thrones.”

Fellow “Thrones” actor Ian Whyte, another ex-basketball player, who portrays a variety of roles on the show (Wun Wun, Dongo the Giant, The Mountain, and various White Walkers), spoke out on Twitter to mourn the loss of his large co-star, saying that he was “very sad” to discover his friend’s “tragic passing,” praising Fingleton for “follow(ing) his dreams” and wishing that he “rest in peace.”