David O'Leary was most recently the manager of Al-Ahli Dubai.
Previously, O'Leary led Leeds United to the semi-finals of the Champions League as the club's most successful manager since Howard Wilkinson won the title in 1992.
Leeds were never out of the top six in the Premier League during O'Leary's four seasons in charge.
The London-born Irishman, who later managed Aston Villa, took over at Elland Road in October, 1998 after ending his playing career with Leeds and then becoming George Graham's assistant.
Graham's departure for Tottenham saw O'Leary make an immediate impact in management. He encouraged an expansive style of play revolving around his faith in younger players like Harry Kewell, Alan Smith, Lee Bowyer and Jonathan Woodgate.
Leeds finished fourth at the end of his first season, qualifying for the UEFA Cup in which they were to reach the last four. Third place in the 1999-2000 campaign hoisted United into the Champions League.
O'Leary's young side took Europe's top clubs by surprise in a run to the semi-finals before losing to Valencia. In the same season Leeds finished fourth in the Premiership, ensuring they remained in Europe via the UEFA Cup.
However, expectations had been raised. Even fifth place in 2002 was not enough to keep O'Leary in his job against a background of off-field problems including a high-profile court case involving Bowyer and Woodgate, and the club's mounting financial difficulties.
O'Leary returned to management with Aston Villa in the summer of 2003 and, in leading them to sixth, achieved an improvement of ten places on the previous campaign. Villa were tenth the following season before injuries and suspensions took their toll, culminating in O'Leary's departure in 2006.
O'Leary was then confirmed as the new manager of Al-Ahli Dubai on July 5, 2010. He remained with the club until April 2011.
As a cultured centre half, he remains Arsenal's all-time record-holder for appearances with 722 first-team games among over 1,000 at all levels.
O'Leary helped the Gunners to six major trophies, including two league titles. He also racked up 67 caps for the Republic of Ireland and was the player who scored the vital penalty in a shoot-out win over Romania that took Jack Charlton's team to the quarter finals of the World Cup in 1990.