Arsenal have formally announced the signing of defender Laurent Koscielny, who joins the Gunners from Lorient in a deal worth a reported £10 million.
The imminent arrival of Koscielny, 24, has been an open secret for weeks but the club confirmed on Wednesday that the centre back has signed a "long-term contract" and been given the No.6 shirt made vacant by Philippe Senderos' move to Fulham.
Koscielny was named Ligue 2's best player for the 2008-09 season when playing for Tours and after joining Lorient 12 months ago, impressed as the club finished seventh in the French top flight last season.
"Koscielny is a central defender with great ability who performed extremely well last season for Lorient," manager Arsene Wenger told the club's official website.
"We identified him as a very strong centre half, who has made big progress very quickly. He has shown he is mentally strong, he's a fighter and a very strong competitor. Koscielny is a great addition to our squad."
Wenger has made no secret of his intent to strengthen Arsenal's defensive options in advance of the new season with Mikael Silvestre, Sol Campbell and William Gallas all out of contract.
With Senderos leaving, Koscielny joins Thomas Vermaelen and Johan Djourou as the only senior centre backs on Arsenal's books. The new signing is expected to make his Emirates Stadium debut when Arsenal host the Emirates Cup at the end of July.
"I'm very excited to be joining Arsenal," Koscielny said. "They are one of the biggest teams in Europe with many great players. I'm really looking forward to playing in the English Premier League and the Champions League with my new club. Also, in Arsene Wenger, Arsenal has one of the best managers in the world and I can't wait to work with him and do my best for the Arsenal supporters."
Arsenal have also signed Moroccan striker Marouane Chamakh on a free transfer this summer and are believed to be one of a number of clubs interested in signing Joe Cole, who is available on a free following his release by Chelsea.