Wigan centre Joel Tomkins has completed his switch from league to union by joining Premiership champions Saracens.
"I will always be a proud Wiganer," said Tomkins.
"But everybody in rugby union and rugby league can see there is something very special happening at Saracens, and I can't wait to be part of it."
Tomkins, who can also operate at second row, was omitted from England's Four Nations squad at his own request.
He played 149 times for his hometown club following his debut in 2005.
The move was hinted at in September when he and his brother, Wigan team-mate Sam, joined former league player Chris Ashton in signing up for a sports management company associated with rugby union clients.
Full-back Sam, 22, has remained in the England rugby league fold, despite his brother's desire not to be included in the squad this autumn for "personal reasons".
Wigan chairman Ian Lenagan said: "Joel wished to move to the south of England and take his chance at rugby union.
"Wigan would not step in the way of a player with such clear ideas to leave. He is joining an excellent club in Saracens."
Winger Ashton left Wigan to become a union player, signing for Northampton Saints four years ago, and has since been capped 18 times by England.
Kyle Eastmond was the most recent high-profile rugby league player to swap codes when the England and St Helens scrum-half joined Bath, but the 21-year-old is yet to make his first appearance.
Tomkins is not the first player to cross the code divide between Wigan and Saracens.
Andy Farrell, who is now Saracens first-team coach, left Warriors in 2005 for north London and went on to feature for England in the 2007 World Cup.
The two clubs have also announced a new partnership with the aim of playing a cross-code game in the future and sharing coaching resources and players.