A historic undisputed heavyweight bout between champions Tyson Fury and Oleksandr Usyk has been signed for Riyadh, Saudi Arabia.

Additional information, including the fight date, has yet to be released.

The WBC champion is Britain’s Fury, 35, and Ukraine’s Usyk, 36, has the WBA, WBO, and IBF championships.

“Delighted to finally get this fight signed,” Queensbury promoter Frank Warren stated. “This is the biggest fight that could possibly be made in our sport.”

The winner will be declared the four-belt era’s first undisputed heavyweight champion.

The fight is scheduled for December 23, although it could be postponed until early next year.

Since turning professional in 2008, Fury has won 33 fights and drawn one.

‘The Gypsy King’ must first avoid injury in a non-title fight against MMA star Francis Ngannou on October 28 in Riyadh.

Usyk, who has won all 21 of his professional fights, defended his belts against Londoner Daniel Dubois in August.

“The heavyweights always spark the imagination of the fans, and I have no doubt this will be the biggest boxing event of the century,” said Warren.

Fury received criticism for failing to negotiate terms with Usyk after a proposed bout at London’s Wembley Stadium in April fell through. From tennis prodigy to boxing world-title contender, Scotland’s Rankin will fight for the WBC belt.

“I still can’t believe it’s happening,” Usyk’s promoter, Alexander Krassyuk, said.

Since 1999, when Lennox Lewis defeated Evander Holyfield to defend his WBA, WBC, and IBF championships, there has been no undisputed heavyweight champion.

“Tyson Fury and Oleksandr Usyk are the two greatest heavyweights of their generation, and I can’t wait to see what happens when they step into the ring in Riyadh,” Bob Arum, the co-promoter of Fury, stated

“They are special talents worthy of competing for the greatest prize in sports.”