Mesut Ozil has completed his transfer to Arsenal from Real Madrid for a club-record £42.5 million.
Ozil, 25, currently on duty with Joachim Low’s Germany squad, underwent a medical in Munich with Bayern doctor Hans-Wilhelm Muller-Wohlfahrt before signing for the Gunners.
The midfielder is reunited with former Werder Bremen team-mate Per Mertesacker at the Emirates and joins fellow Germany international Lukas Podolski.
The deal has made him the most expensive player ever sold by Real Madrid, breaking the record held by Robinho's £32.5 million move to Manchester City in 2008.
He eclipses Bayern Munich’s Mario Gotze, who made a €37 million switch from Borussia Dortmund earlier in the summer, as the most expensive-ever German player.
Ozil's move comes at the end of a transfer window which has seen Arsenal frustrated by their failure to land Gonzalo Higuain, who left Real for Napoli, and Luis Suarez.
Arsene Wenger told the club's official website: "We are extremely pleased to have signed Mesut Ozil. He is a great player, with proven quality at both club and international level. We have watched and admired him for some time as he has all the attributes I look for in an Arsenal player.
"I have said throughout the summer that we have been working hard to bring in top quality players to this football club. This has involved many many people across the club and I have always had the full support of the club in making decisions on the football side.
"Mesut is a top quality footballer who will be a fantastic addition to our talented squad. We are all looking forward to him joining up with us after his international matches with Germany and working with us as an Arsenal player."
Ozil said: "I am thrilled to be joining a club of the stature of Arsenal and am looking forward to playing in the Premier League. It will be great for my own personal development as a player and I am particularly looking forward to working with Arsene Wenger.
"From our negotiations it is clear the club has huge ambition and I look forward to being part of an exciting future."
Ozil added on his Facebook page: "Dear fans of Real Madrid. Thank you very much for three wonderful years with all of you. My time at Real Madrid was unique and special for me. Sometimes things develop differently, than I would have expected them to a few days ago.
"Although I’m leaving Real Madrid I wish you and the team the very best for the future. Now I’m looking forward to my new club: THE GUNNERS!"
Madrid, having finally agreed the world-record signing of Gareth Bale on Sunday, also allowed Kaka to join AC Milan on a free transfer on Monday.