Craig Dawson has joined Watford for a deal believed to be worth £5.5 million.
The 29-year-old defender had a year left on his contract and showed little intention of signing a new deal.
He joined from Rochdale back in 2010 for a six figure sum and went on to make 225 appearances in all competitions for Albion, scoring 15 goals.
Dawson initially struggled at Albion and was loaned out to Bolton in January 2013. He returned the following season and only established himself in Albion's side when former Baggies boss converted the defender to a right-back.
The defender pushed for a move away from the club last season and refused to go on the club's pre-season tour and to even wear club clothing around the training ground.
He was reintegrated into the first team when a moved failed to materialise and made 45 appearnces in total last season.