Burnley have signed Jack Cork from Swansea on a four-year deal for a fee Sky sources understand is worth £10m.
It will be the second time Cork has used the home changing room at Turf Moor, the 28-year-old midfielder having made 57 appearances for Burnley while on loan from Chelsea seven years ago.
Cork told Burnley's website: "It's great to be back. I've got some great memories from the year-and-a-half I was here and it's good to come back and see some old faces.
"It's good to come back and try and have another go here, especially in the Premier League. It's a new challenge for me and one I'm excited for and I'm looking forward to meeting new people."
Cork signed for Southampton in 2011 and he helped the Saints win promotion to the Premier League in 2012.
Swansea completed his signing in the 2015 January transfer window and he quickly became a regular starter at the Liberty Stadium, making 82 appearances and captaining the team for much of last season.
He becomes Sean Dyche's third new recruit of the summer following the arrivals of Charlie Taylor and Jonathan Walters from Leeds and Stoke City respectively.