Gerard Houllier has resigned as manager of Aston Villa due to concerns over his health.
The decision had been expected for some time after Houllier was rushed to hospital in April with chest pains which turned out to be a dissection of the descending aorta.
Houllier, who underwent major heart surgery when manager of Liverpool ten years ago, was unable to return to work for the remainder of the season. Gary McAllister took the reins on a caretaker basis.
And Houllier, 63, has decided to step down from the Villa job, which he took in September 2010 shortly after Martin O'Neill walked out on the Villans.
Gerard Houllier said: "I am extremely disappointed that I will not have the opportunity to manage Aston Villa next season. My health has improved considerably since I was taken ill on April 20. I now intend to take the next few months to concentrate on recuperating fully before I may return to football.
"I was very much looking forward to the prospect of my first full season as Villa manager and returning for pre-season training to prepare for the campaign ahead, a luxury that I did not have last season. I have been extremely touched by all of the messages I have received and by the reaction of people throughout the world of football.
"I am very grateful to the Villa fans for their genuine concern and encouragement and to the fans of clubs up and down the country for their kind sentiments. I would especially like to thank my assistant manager, Gary McAllister, my staff, the players and all at Aston Villa for their support and, of course, for their efforts in securing a very positive end to last season.
"It has been an honour to manage this great club and I wish everyone connected with Aston Villa every success for the future."
A statement issued on the club's official website by chief executive Paul Faulkner read: "I would like to thank Gerard for his considerable efforts over the past nine months and for the dedication, commitment and work ethic he has demonstrated as Villa manager.
"We regret the circumstances of Gerard's departure and, naturally, we wish him well in his continued recovery. I know I speak for everyone associated with Aston Villa in expressing our hope that Gerard will return to full health as quickly as possible and we wish him all the best for the future.
"As a Board we are very conscious of the need to ensure that the Club is prepared fully to meet the demands of the new season and, to that end, we have already embarked upon the process which will lead to the appointment of a new manager.
"We will update when appropriate and until such time as we can make an announcement there will be no further comment from the Club on this matter."
Villa's record signing Darren Bent has revealed his sadness at Houllier having to stand down. He showed his faith in Bent by splashing out an initial £18 million to Sunderland in January and he responded with nine goals in 16 games.
Bent said: "It is sad for me to see Gerard go. He signed me, invested a lot of money in me. He showed a lot of faith in me. But your health comes first and, if he's not well enough to come back, then he needs to take a break.''