Manchester United have confirmed Sir Alex Ferguson will step down as manager at the end of the current Premier League season after more than 26 years in charge.
Ferguson, 71, who took charge in November 1986, will become a director at the club. His last game in charge of the new champions will be at West Bromwich Albion on May 19 - his 1500th match.
Real Madrid coach Jose Mourinho and Everton boss David Moyes are the front-runners to replace him.
Ferguson, who joined United from Scottish side Aberdeen, has won 13 Premier League titles, two Champions League trophies, the FA Cup five times and four League Cups with United.
He also steered the club to two Champions League triumphs and FIFA's Club World Cup.
"The decision to retire is one that I have thought a great deal about and one that I have not taken lightly," said Ferguson, who is set to have a hip operation in the close season. "It is the right time.
"It was important to me to leave an organisation in the strongest possible shape and I believe I have done so.
"The quality of this league winning squad, and the balance of ages within it, bodes well for continued success at the highest level whilst the structure of the youth set-up will ensure that the long-term future of the club remains a bright one.
“Going forward, I am delighted to take on the roles of both director and ambassador for the club.”
After ending the Celtic-Rangers "Old Firm" dominance of Scottish football with Aberdeen, Glasgow-born Ferguson took over at United with the club having not been English champions since 1967. After a tricky few years when he was reported to be under pressure, he won his first trophy, the FA Cup, in 1990.
The European Cup Winners' Cup and League Cup followed in the next two seasons, but it was when United won the newly-formed Premier League in 1993, ending a wait of 26 years to be champions, that his legend really began.
The Double of league and FA Cup followed twice in the next three seasons and in 1999 he won the first of his two European Cups with a heart-stopping win over Bayern Munich.
It was at the end of that game in Barcelona, which United won 2-1 thanks to two injury-time goals to cement the Treble of league, FA Cup and European Cup, where Ferguson came out with his immortal line: "Football, bloody hell."
Another oft-repeated statement of Ferguson, from not long after his appointment as United boss, was that he wanted to knock Liverpool, then the dominant force in English football, "off their ******* perch". He achieved that two seasons ago when he led United to their 19th league title - one more than Liverpool's old record of 18.
United extended that mark to 20 this season.
During his time in charge, Ferguson launched the careers of players such as David Beckham, Ryan Giggs and Paul Scholes. He has also managed Eric Cantona, Roy Keane, Cristiano Ronaldo and Wayne Rooney.
Manchester United co-chairman Avie Glazer says: "I am delighted to announce that Alex has agreed to stay with the club as a director.
"His contributions to Manchester United over the last 26 years have been extraordinary and, like all United fans, I want him to be a part of its future."
United chief executive David Gill said: "The way he cares for this club, his staff and for the football family in general is something that I admire. It is a side to him that is often hidden from public view, but it is something that I have been privileged to witness in the last 16 years."
Tributes also came in from rivals and officials.
Fifa president Sepp Blatter said: "Just heard Sir Alex Ferguson is retiring at end of season. His achievements in the game place him without doubt as one of the 'greats'. Was honour to present Sir Alex with award at 2011 Ballon D'Or. Will his longevity at the top ever be repeated?"
Manchsester City skipper Vincent Kompany said: "Sir Alex, one of the best managers of all time. After 26 years of success in the game, we all owe him a tribute."
FactboxName: Alexander Chapman Ferguson
Date of birth: December 31, 1941
Place of birth: Glasgow, Scotland
Playing careerPosition: Striker
Teams: Queen’s Park (1957-1960), St Johnstone (1960-1964), Dunfermline Athletic (1964-1967), Rangers (1967-1969), Falkirk (1969-1973), Ayr United (1973-1974)
Playing honoursSt Johnstone
Scottish Football League Division Two (1): 1962-63
Scottish Football League Division Two (1): 1969-70
Managerial careerTeams: East Stirlingshire (1974), St Mirren (1974-1978), Aberdeen (1978-1986), Scotland (1985-1986), Manchester United (1986-2013)
Managerial honoursSt Mirren
Scottish First Division (1): 1976-77
AberdeenScottish Premier Division (3): 1979-80, 1983-84, 1984-85
Scottish Cup (4): 1981-82, 1982-83, 1983-84, 1985-86
Scottish League Cup (1): 1985-86
UEFA Cup Winners’ Cup (1): 1982-83
Manchester UnitedPremier League (13): 1992-93, 1993-94, 1995-96, 1996-97, 1998-99, 1999-2000, 2000-01, 2002-03, 2006-07, 2007-08, 2008-09, 2010-11, 2012-13
FA Cup (5): 1989-90, 1993-94, 1995-96, 1998-99, 2003-04
League Cup (4): 1991-92, 2005-06, 2008-09, 2009-10
Community Shield (10): 1990 (shared), 1993, 1994, 1996, 1997, 2003, 2007, 2008, 2010, 2011
UEFA Champions League (2): 1998-99, 2007-08
UEFA Cup Winners’ Cup (1): 1990-91
UEFA Super Cup (1): 1991
Intercontinental Cup (1): 1999
FIFA Club World Cup (1): 2008
IndividualPremier League Manager of the Season (10): 1993-94, 1995-96, 1996-97, 1998-99, 1999-2000, 2002-03, 2006-07, 2007-08, 2008-09, 2010-11
UEFA Manager of the Year (1): 1998-99
BBC Sports Personality of the Year Coach Award (1): 1999
BBC Sports Personality of the Year Lifetime Achievement Award (1): 2001
English Football Hall of Fame (Manager) : 2002
European Hall of Fame (Manager): 2008
FIFA Presidential Award: 2011
OtherOfficer of the Order of the British Empire (OBE): 1983
Commander of the Order of the British Empire (CBE): 1995
Knight Bachelor (Kt.): 1999