West Ham have completed a deal to bring James Collins back to the club from Aston Villa on a four-year contract.
The Hammers agreed a fee with Villa earlier in the week and Sky Sports revealed on Tuesday that Collins had travelled to London to undergo a medical.
It has now been confirmed that Collins has returned to Upton Park, having spent four years with the club earlier in his career before moving to Villa in 2009.
Sam Allardyce has been looking to bolster his defence since winning promotion back to the Premier League and Collins will now face the challenge of trying to establish himself as a regular member of the starting XI.
The Wales international, 28, is thrilled to have joined the Hammers once again and hopes to make an important contribution over the next few years.
"It's great to be back," he told the club's official website.
"Obviously having been here before and coming back and seeing some of the same old faces is great.
"As soon as I knew the interest was there from West Ham I couldn't wait to get down and sign. I had a great affinity with the club and the fans when I was here the first time and I enjoyed my time here so much last time that it wasn't a hard decision to make, to be honest.
"I think everyone knew that I didn't really want to leave when I did [in 2009] because I was enjoying my time here so much.
"I've come back and I'm a much better player this time around so I can't wait to get cracking and show the fans that I am a better player and can put in the performances on the pitch.
"I've got so many good memories - getting into the FA Cup final in my first season and finishing so high [ninth] in the league and then the way we escaped relegation that year was one of my fondest memories in football. Hopefully I won't have too many more memories like that!
"I just cannot wait to get back and show the fans what a better player I am now."