Borussia Dortmund midfielder Ilkay Gundogan has joined Manchester City on a four-year deal.
Gundogan, 25, becomes the first new arrival of manager Pep Guardiola's tenure at the Etihad Stadium after completing a move for a reported £21 million.
The Germany international is currently recovering from surgery after he dislocated his kneecap in training.
@MCFC ANNOUNCE GUNDOGAN! ��
- Ilkay Gündogan (@Guendogan8) June 2, 2016
"I'm thrilled to have signed for Manchester City," Gundogan said on City's official website. "When I learned of City's interest my heart was set on coming here and things have moved very quickly.
"I have loved my time with Borussia Dortmund and I would like to thank the club and the supporters for the five very happy years I spent there.
"They gave me a platform to play on and I became a better player because of the belief, patience and trust they showed in me.
"Now I have a new challenge and that is to achieve great things with City. The opportunity to work with a coach like Pep Guardiola is something I am really looking forward to and I am flattered to be the first signing the Club has made this summer.
"I can promise the City fans I will give everything to help us win titles both in England and the Champions League. These are exciting times.
"I have my best years ahead of me and I think we can achieve great things together. I can't wait to begin this new chapter in my career."
.@Guendogan8 signs for City! #WelcomeIlkay #mcfc https://t.co/a5Nkykajbl
- Manchester City FC (@MCFC) June 2, 2016
Gundogan will miss this summer's European Championships and will not be back for City's preseason tour to China, which includes a game against Dortmund. However, it is hoped the deep-lying playmaker could be back in action by September.
The Gelsenkirchen-born player had just over 12 months remaining on his contract with Dortmund. The Bundesliga club had offered a new long-term deal and had told him they were unwilling to go into the new season with the midfielder's future undecided, although they later backtracked on that.
Gundogan won the Bundesliga and cup Double at Dortmund in 2012 and helped his side to the Champions League final the following season, which they lost 2-1 to domestic rivals Bayern Munich at Wembley.
However, he played just 57 minutes of the 2013-14 season before missing the next 15 months with a back injury.
Gundogan is the second high-profile departure from Dortmund this summer following club captain Mats Hummels' return to Bayern.
City's director of football Txiki Begiristain added: "Ilkay is an excellent addition to our team and we are delighted to have him on board.
"He is an intelligent and versatile midfielder who can operate in a number of different roles. I think our supporters will enjoy his work ethic and technical ability and I believe he will be a very important player for us in the coming years."
Dortmund sporting director Michael Zorc said: "We would like to thank Ilkay Gundogan for five extraordinary years at Dortmund. BVB wishes him a speedy recovery and all the best for his future at Manchester City."