South Africa flanker Schalk Burger has agreed to join Aviva Premiership champions Saracens on a two-year deal that expires in 2018.
Burger, a veteran of four World Cups and a winner of the sport's greatest prize in 2007, will arrive at Allianz Park next season upon completion of spells at Japanese club Suntory Sungoliath and Super Rugby province Stormers.
The 32-year-old back row, who was a key player for South Africa during their march to the semi-finals at England 2015, has been capped 86 times and was named world player of the year in 2004.
"I'm delighted to be joining Saracens. I'm extremely excited to have the opportunity to play in both the Premiership and European Cup - two of the leading competitions in world rugby - for such a special club," Burger said.
"It's an exciting challenge for me and my family and hopefully I can add a lot of value on and off the field to an already successful group of players and coaches."
Recruiting Burger is a major coup for the Premiership leaders, who have been looking to strengthen due to this season's departure of Ernst Joubert and Jacques Burger.
Burger holds the record for the most caps accumulated and most tries scored by a Springbok flanker and can play across the back row, although he is most at home in the number six jersey.
South Africa built their gameplan around him at last autumn's World Cup, repeatedly using him at first receiver where he would either carry, clear out a ruck or feed the ball to his fly-half or wing.
He has been troubled by neck and knee injuries in the past, but his darkest hour came in 2013 when surgery to relieve pressure on a nerve resulted in him contracting a hospital bug that led to bacterial meningitis.
A four-day spell in isolation in intensive care led to fears for his life, but he recovered and was able to play again by the end of the season.
Director of rugby Mark McCall insists Saracens - the only unbeaten team in Europe this season - have signed one of the sport's outstanding players.
"Schalk is a Springbok legend and will add a huge amount of experience and quality to our young English forwards," McCall said.
"We have always talked about having the right blend of experience and youth in our squad, so to be able to add one of the world's finest players to the group is extremely exciting news.
"By the beginning of next season we will have lost two highly experienced back row forwards in Ernst Joubert and Jacques Burger, so to have a player of Schalk's calibre coming into the squad is fantastic news.
"He is a man who has achieved everything there is to achieve in the game of rugby. Not only is he a fine rugby player, he is a humble and down to earth guy who we believe we will fit into the Saracens environment."