Southampton have confirmed Harry Redknapp has taken over as manager.
The former Portsmouth boss has been given an 18-month contract and replaces Steve Wigley, who managed just one win in 14 league games in charge.
Redknapp said: "I am delighted to join Southampton. The squad is better than their position suggests and I look forward to getting them up the table."
Chairman Rupert Lowe added that Wigley was asked to stay at the club but decided to make a "clean break".
At a news conference, Redknapp said he did not know if Jim Smith, his assistant at Portsmouth, would be joining him at St Mary's.
Redknapp, 57, quit his Fratton Park position on 24 November and vowed: "I will not go down the road - no chance."
"Both sets of fans are full of passion and appreciate the sort of football I play," he said.
"I can't think of a similar situation on the south coast but I don't see a problem with the vast majority of either fans.
"The game on 23 April (when the two clubs next meet) will be a cracker."
Redknapp became a cult hero after leading Portsmouth into the Premiership for the first time, and then masterminding their survival in their debut season.
But he left the club claiming he needed a break from football, though many believed he was upset with chairman Milan Mandaric's decision to bring in Velimir Zajec as executive director.
Mandaric admitted he was "disappointed" by Redknapp's move to Southampton and also said he believed negotiations had been going on "for some time".
But in a statement on the Southampton website, Lowe insisted: "We first discussed his appointment two days ago."
Lowe said he regretted the departure of Wigley, the former academy director who replaced Paul Sturrock just two games into the season.
"I am unapologetic about giving young managers a chance, and always hope they succeed," he said.
"However I have a responsibility for the future of the club and together with the board felt that a change at the top was the only way to turn our season around."
REDKNAPP THE MANAGER
December 1982: Becomes caretaker-boss at Bournemouth - loses first game 9-0 at Lincoln
October 1983: Appointed full-time Cherries manager
June 1992: Resigns as Bournemouth boss. Joins West Ham as assistant to Billy Bonds
August 1994: Named West Ham boss after Bonds resigns
May 2001: Resigns after finishing 14th in Premiership
June 2001: Joins Portsmouth as director of football
March 2002: Replaces Graham Rix as Pompey boss
24 November 2004: Resigns as Pompey manager
8 December 2004: Takes over as Southampton boss
Redknapp is Southampton's ninth manager in eight years, and Lowe said he hoped it would bring stability to the club.
"Twelve months ago, this club was fourth in the Premiership - and since then our footballing performance has been in steady decline," he said.
"While the savage level of injuries at the end of last season and to a lesser degree this season have played their part, we have not been able to achieve the level of management stability that would allow the club to perform at its best.
"I and the board must shoulder responsibility for this.
"Harry brings with him 900 games of management expertise and is a fabulous
"On top of that he brings a media presence that we hope will change the tone of the coverage the club receives."