England international Nick Kennedy joined English Premiership club Harlequins from European champions Toulon on Wednesday.
Kennedy, who won seven England caps between 2008 and 2009, failed to settle at Toulon and returns to the Premiership after one season with the French side.
Harlequins were in the market for a lock after Olly Kohn retired due to a shoulder injury and they moved quickly to snap up Kennedy once Toulon agreed to let him leave.
Conor O'Shea, Harlequins' director of rugby, gave Kennedy his break at London Irish and he said: "Nick has sacrificed a valuable contract at Toulon to return to England where he feels he has unfinished business.
"His ambition is pretty clear in that he wants to win the Premiership and force his way back into the England squad ahead of the Rugby World Cup in 2015.
"I've known him since he came to professional rugby and I know that in Nick we have a player and a person who will fit into what this club is all about."
Kennedy, 31, struggled to adapt to life at Toulon after his long spell in the Premiership with London Irish.
But Kennedy insisted he had no regrets about joining Toulon because he was able to play a part in the club's European Cup final victory over Clermont in Dublin.
"I've had a memorable year in the south of France and winning the European Cup with Toulon will rank among the highlights of my career," Kennedy said.
"The opportunity to return to England and join Harlequins has come at the right time for me. I'm looking forward to the challenge and to being part of an exciting squad of talented players."
Toulon announced on Tuesday that New Zealand lock Ali Williams will join the club to replace Kennedy.