Arsenal have formally confirmed that Arsene Wenger has broken his rule of never re-signing a former player to bring two-time Premier League winner Sol Campbell back to the club on a deal to the end of the season.
Campbell, 35, had been training with his former club in an effort to maintain his fitness following his acrimonious departure from League Two Notts County in September.
However, with Philippe Senderos poised to leave the club and Johan Djourou sidelined with a long-term injury, Wenger has been sufficiently impressed by Campbell's performances at London Colney to offer the defender a contract until the end of the season.
The news represents an unexpected return to North London for Campbell, who emerged from Tottenham's youth academy before joining bitter rivals Arsenal on a free transfer in July 2001. In his first spell with the Gunners, Campbell won two Premier League titles and three FA Cups, as well as going the league season unbeaten in 2003-04.
"We are delighted to have signed Sol Campbell until the end of the season," Wenger told the club's official website. "For both club and country, Sol's career just speaks for itself.
"He is a hugely experienced and intelligent footballer, who will bring a great amount of quality and knowledge to our squad. Sol as a player and a person will be an enormous asset to us.
"Sol has been training with us since September and during this time he has shown he still has the required fitness, hunger and passion to compete at the top level."
Campbell added: "I'm so happy to be rejoining Arsenal. I have many great memories from being here before and still have many friends at the Club. I've been working very hard at the Arsenal training ground, I feel really good at the moment and I'm ready to give my all. We're in a strong position and I want to help Arsenal be successful this season."
Campbell, who is fourth on the all-time Premier League appearance list with 462 games under his belt, left Arsenal in the summer of 2006 to join Portsmouth and won the FA Cup for a fourth time under Harry Redknapp.
However, his abortive move to Notts County was far less successful as he made only one appearance for the League Two club after being lured to Meadow Lane by former England manager Sven Goran Eriksson, who coached Campbell at three major tournaments.
Meanwhile, fringe defender Kerrea Gilbert has joined Peterborough on loan until the end of the current campaign.