Celtic have confirmed the departure of Stephen McManus to Middlesbrough on a three-year contract.
The former Hoops captain's move to the Championship was announced on Tuesday after the defender impressed while spending the second half of last season on loan at The Riverside.
Centre-back McManus links up with former Celtic boss Gordon Strachan, as well as ex-team-mates Barry Robson, Chris Killen, Willo Flood and Scott McDonald.
"Celtic football club has bid farewell to their former captain, Stephen McManus, after 10 successful years at the Hoops," said a statement on Celtic's official website.
"The 27-year-old has joined Gordon Strachan at Middlesbrough after spending the remainder of last season on loan to the Championship side.
"McManus was a product of Celtic's youth Academy before making his first-team debut in 2003 and was handed the captaincy on a permanent basis when Neil Lennon left the club four years later.
"The defender meets up with former Celts Scott McDonald and Willo Flood as he signs a three-year deal with the English side.
"Everyone at the club offers Stephen and his family their sincere best wishes for the future and thanks him for his great contribution to the club."
McManus, the fourth man to join Boro this summer following the arrivals of Andy Halliday, Kris Boyd and Nicky Bailey, is thrilled pen a permanent deal at the club after enjoying his time in English football last season.
"I was lucky to have 12 great years with Celtic, right from leaving school. I was sad to go but it was the right time for me to move on," McManus told Boro's official website.
"I really enjoyed my time at Middlesbrough last season. Everyone has been great with me here right from the off.
"The manager made it clear to me how much he wanted me to come here and in any line of work, you want to go where you are most wanted.
"In terms of the decision, I wanted to know what the manager's thoughts and plans were for the future.
"Obviously the signings the club has already made are impressive, while it's clear from speaking to him that the manager is ambitious.
"All the lads here are ambitious. This club should be in the Premiership, so promotion is the aim.
"The Championship is a tough league, but the aim is to go up. It's a big challenge for all of us, but one I am looking forward to."