The former centre half joined Arsenal from their north London rivals in 2001
The transfer window is in full swing with clubs in the Premier League and across Europe seeking deals
The stakes are always high in the north London derby, but much was riding on this one for Mikel Arteta and his team, as a season that started with so much optimism and expectation threatened to flounder. The scenes at the end of this win over Spurs were wild, noisy and laced with relief as much as celebration. Arsenal had known anything less than victory over their arch-rivals would put a serious dent in their title pursuit.
In a new BBC documentary, key figures associated with Real Madrid discuss why the club is so successful in the Champions League.