Jonny Evans has completed his move to West Brom from Manchester United.
The Northern Ireland defender, 27, has joined the Baggies for an undisclosed fee, with reports suggesting it is £6m plus £2m in add-ons.
"This is a great signing for the club," said Albion boss Tony Pulis, whose side won 1-0 at Stoke on Saturday.
"Jonny brings a lot of experience and will be a big player for us - he's a player I've been watching for some time and we are delighted to have him."
Evans made 198 appearances for United and won three Premier League titles at Old Trafford but had fallen out of favour under manager Louis van Gaal.
The centre-back, who had two loan spells at Sunderland, has not featured for United at all this season and had also been linked with Everton.
Evans will link up with former Red Devils team-mate Darren Fletcher, who left United in January and has since been appointed West Brom's captain.
In March, Evans was involved in a controversial spitting incident with Newcastle striker Papiss Cisse.
He was given a six-match ban by the Football Association and has featured just once for United since.