Younes Kaboul has joined Sunderland from Premier League rivals Tottenham Hotspur on a four-year deal.
The Frenchman had been closing in on a move to the Stadium of Light after passing a medical on Thursday evening.
Kaboul, who has spent six years at Spurs across two separate spells, was previously linked with moves to both Everton and Watford.
However, Sunderland have now completed the capture for an undisclosed fee, which is thought to be in the region of £3m.
"I'm delighted to be a Sunderland player and it's an honour to join this club," he told his new side's official website. "I would like to thank Lee Congerton and the head coach for making this move possible and I can't wait to start playing for the Sunderland supporters."