Arsenal have confirmed that Per Mertesacker has joined the club from Werder Bremen.
Mertesacker, 26, arrives to bolster the Gunners' defence along with left-back Andre Santos, with Arsene Wenger determined to shore up his backline in the wake of Sunday's 8-2 humiliation at the hands of Manchester United.
The Germany international is believed to have cost Arsenal around £10 million and offers the North Londoners a wealth of experience in European and international competition, having played in the 2009 Europa League final with Werder and the 2006 and 2010 World Cups with Germany.
"We are delighted to welcome Per Mertesacker to the Club," said Arsene Wenger. "He is a German international with vast experience and strength and is good on the floor and in the air. I believe he will be well-suited to the Premier League and a tremendous asset to the team."
Mertesacker told Werder Bremen's official website: "I had a great time at Werder, and I owe a lot to the club. The move to London is a wish come true, to take another step in my career. The English Premier League has for me always represented an interesting challenge.''
Bremen coach Thomas Schaaf said of Mertesacker's impending departure: ''On the one hand we are sad because we still wanted to achieve a lot with Per, but on the other hand, we know how much he is attracted by the English Premier League. We had a great time and we wish Per all the best with Arsenal.''
The 6' 6'' centre-back has now passed a medical and agreed terms, confirming on his personal website that he has signed a contract until 2015.