Hafthor Bjornsson
Icelandic strongman Hafthor Bjornsson played "The Mountain" on the hit HBO series "Game of Thrones." HBO

Professional strongman and “Game of Thrones” star Hafthor Bjornsson is breaking more than just Prince Oberyn Martell's skull these days. The competitive weightlifter purportedly broke a 1,000-year-old Vikings record by taking five steps with a 32-foot-long, 1,433-pound log on his back during a victorious performance at the Jan. 31 “World’s Strongest Viking” competition in Norway, reports said.

“The record has been described in Icelandic Saga book. The legend of the Icelander Orm Storulffson says that he walked three steps with this monster wooden log which weighed over 650kg and was 10m long … Thor carried the 650kg and 10m log for 5 steps. The result was unbelievable and puts Hafthor Julius Bjornsson in Viking history books,” strongman promoter Ilkka Kinnunen told weightlifting website IronMind.com, including quotes from Bjornsson's Instagram account.

Bjornsson, who stands 6-foot-9 and weighs 400 pounds, won the World’s Strongest Viking competition for the second consecutive year, according to his Instagram account. He has finished in third place at the “World’s Strongest Man” competition in 2012 and 2013 and was named runner-up in 2014, according to the Daily Mail. He also earned the title of “Europe’s Strongest Man” last August.

The 26-year-old took to Instagram on Saturday to discuss his next weightlifting goal. “As well as winning the title of The World’s Strongest Viking for the second time in a row I carried this monster log 5 steps … As I’m on my way to my ultimate goal to win The World’s Strongest Man! Nothing can stop me!!” Bjornson wrote. But Bjornsson is best known for his guest appearance in the fourth season of HBO’s “Game of Thrones”, where he played the infamous knight Gregor “The Mountain That Rides” Clegane. The Mountain’s duel with Prince Oberyn is one of the season’s climatic scenes.

This isn’t the first time that Bjornsson’s physical feats have driven the Internet into a frenzy. The Icelandic strongman performed a deadlift of nearly 1,000 pounds of heavy-duty tires at the 2014 Arnold Strongman Classic, according to Gawker. His abilities also caught the attention of the NFL’s Indianapolis Colts, who nearly signed him in 2013, according to CBS Sports. A video of Bjornsson’s Viking record-breaking feat can be viewed below.