By Phil McNulty
Chief football writer
Kevin Keegan has walked away from football for the final time - the end of his Manchester City reign typical of his turbulent career in management.
CITY UNDER KEEGAN
May 02: Win old Div One title with 108 goals
May 03: Finish ninth in Premiership
Nov 03: Knocked out of Uefa Cup by Polish minnows Groclin
Feb 04: 10-man City beat Spurs 4-3 in FA Cup having trailed 3-0
Mar 04: Beat Man Utd 4-1 at Eastlands
Jan 05: Knocked out of FA Cup by Oldham
Mar 05: Parts company with club
Keegan's critics will revive his reputation as a serial "quitter", leaving City just days after insisting he would stay until the summer of 2006.
It is another dramatic chapter in the story of one of football's most honest and endearing characters, a story that has mixed glorious highs with desperate lows.
Keegan has walked away from City, as he walked away from Newcastle United and, most dramatically of all, England.
And the 54-year-old Yorkshireman leaves City with the old questions still being asked about his management style.
Keegan was not a man for the tactics board, relying on raw talent and use of the chequebook - it made for occasional exhiliration, but ultimately little silverware.
As he said himself: "If it's a 0-0 draw in the Ukraine you want, then I'm probably not your man."
His critics harshly judged him as a man who was more cheerleader than manager, a man to provide an initial spark but not the nous and know-how to provide long-term stability and success.
Keegan's approach appeared to come more from the heart - worn so obviously on the sleeve - than the head.
But this is an extreme verdict on a man whose teams brought plenty of pleasure along with the pain.
He was ridiculed for his "I'd love it if we beat them" rant at Sir Alex Ferguson as the 1996 title slipped away, but that was why supporters related to Keegan.
Former Newcastle and Manchester City defender Steve Howey said: "At Newcastle he was different class. He was like one of the players, running around and joining in.
"At Manchester City he was a bit different - maybe because of the England scenario.
"But there was always a glint in his eye - he used to come into work like a little boy in a sweetshop."
But his failure to go the distance at clubs leaves him as an unfulfilled managerial talent.
He took Newcastle to the brink of the Premiership title, but was broken by the squandering of a 12-point lead in 1996, a situation not helped by an uneasy relationship with the club's hierarchy.
Former striker Les Ferdinand believes Keegan never recovered from that harrowing experience.
He told BBC Sport: "Had we won the league that season, things would have been different for Kevin, without a shadow of a doubt.
"For one, I think he would still be at Newcastle and I think he would have proved a point to himself that he could win the championship playing with a team the way we played.
"Unfortunately in football, especially in the Premiership, you need to defend as well as attack. I think in all honesty he has never recovered from that."
Keegan quit England after a World Cup defeat against Germany in the last game at the old Wembley on October 2000, walking into a storm of criticism.
Steve McManaman - disastrous Keegan signing
He also left Fulham after a successful stint as manager, but that was for the understandable temptation of leading his country.
Ironically, Keegan's reasons for walking out on England were exactly those his critics pounded him with - namely that tactically he was simply not up to the unique demands of international football.
Rehabilitation came in the shape of Manchester City in May 2001 as Keegan stepped on another roller-coaster ride.
Promotion to the Premiership in scintilliating fashion, a sojourn into Europe, and two devastating victories against the old enemy Manchester United.
Manchester City is a club held in great affection, but with a glorious unpredictability, a flair for the dramatic and an occasionally unerring accuracy when shooting itself in the foot.
So they had the perfect manager in Keegan.
But momentum has been lost in recent times, and this decent man, a shining beacon of integrity in the game, has looked worn down by the cares of management.
Keegan was also in danger of becoming a lame duck manager, creating an air of uncertainty by confirming he would leave in 2006.
He was also betrayed by poor signings as he spent £50m at City, signing David Seaman - whose mistake led to his England departure - when he was clearly past his best.
Keegan's capture of Steve McManaman has also proved disastrous, while Robbie Fowler and Trevor Sinclair have not delivered.
But there was also the development of Shaun Wright-Phillips and the rebuilding of Richard Dunne's career.
He may have given a clue to his dramatic departure in a candid interview with BBC Radio Five Live just days before he left.
Bemoaning the domination of Chelsea, Arsenal and Manchester United, he said: "In four or five years there won't be much interest in the league. Fans will say it's not worth going to games."
Not the words of a man fired up for future successes. Not the message of a man relishing battles ahead.
And once Keegan started to show his careworn side, then history should have told us the credits were rolling.
Keegan's story has not had a happy ending, but to judge him a failure in management would be wrong.
He rebuilt Newcastle and is still adored on Tyneside. He put Fulham on the road back to the Premiership.
Keegan, albeit with hefty use of the chequebook, restored Manchester City to the top-flight.
So while Keegan's detractors may delight in his departure, he has been a force for good in football and his presence will be missed.