Northern Ireland international Paddy McNair has completed his move from Sunderland to north-east neighbours Middlesbrough.
The 23-year-old, who dropped out of the Championship with the Black Cats last season, will make an immediate return with Boro for around £5m after signing a four-year contract.
A statement on the club's website said: "Boro have completed the signing of Paddy McNair from Sunderland. The highly-rated 23-year-old midfielder joins on a four-year contract. McNair, with 20 Northern Ireland caps, becomes Boro's first signing of the summer."
McNair started out at Manchester United, where he made 27 appearances, but headed for Sunderland in August 2016 in a joint £5.5m deal with Donald Love.
Injuries limited the Ulsterman, who can play defence and midfield, to 28 outings, though he scored seven goals - four in his last five games.
New chairman Stewart Donald and manager Jack Ross had hoped to keep him, but were told he wanted to leave.