Stoke have signed defender Danny Collins from Sunderland for £2.75m.
The 29-year-old, whose fee could rise to £3.5m, follows Uruguayan Diego Arismendi, Robert Huth, Tuncay and Dean Whitehead into the Britannia Stadium.
Potters boss Tony Pulis told the club's official website: "Danny has been Sunderland's player of the year for the past two seasons which speaks volumes for the impact he has had at that level."
Pulis added: "He can play at left-back or centre-half which gives us further options along the back four."
Wales international Collins, who joined the Black Cats in October 2004, will join former Black Cats team-mates Whitehead, Liam Lawrence, Thomas Sorensen, Danny Higginbotham and Rory Delap at Stoke.
He said: "One of the great things about this move is that I will have some familiar faces around me with so many ex-Sunderland players already here. Why, the club even plays in red and white stripes as well.
"All this has happened so quickly because only a few weeks ago I was captaining the Sunderland side in their pre-season friendlies, but Steve Bruce made it clear he was going to bring in new faces and couldn't guarantee me a place.
"Therefore, when I was made aware of Stoke's interest, I thought it was a good time to move on and seek a fresh challenge.
"In many respects the two clubs are alike in that they have big ambitions to finish in the top half of the table this season."