Sir Alex Ferguson was manager at Manchester United for 27 years but the club are now looking for their fifth full-time boss since the Scot retired in 2013.
Here, the PA news agency looks at the record of those to have followed Ferguson.
David Moyes (June 2013-April 2014)
P51 W27 D9 L15 Trophies: 0
The Scot was seen as the ideal Ferguson successor and handed a six-year contract but, after 11 years at Everton, he lasted just 10 months at Old Trafford, paying the price for a dismal campaign in which United failed to qualify for the Champions League for the first time since 1995. After years of further struggle at various clubs, Moyes has kickstarted his career as manager of West Ham.
Louis Van Gaal (May 2014-May 2016)
P103 W54 D25 L24 Trophies: 1
The tough-talking Dutchman delivered the FA Cup in his second season but United’s fifth-placed finish in the Premier League, coupled with criticism of his side’s ponderous style and lack of goals, led to his departure. Van Gaal recently returned to management as Holland’s head coach – a position he left to head to United.
Jose Mourinho (May 2016-December 2018)
P144 W84 D32 L28 Trophies: 2
The much-decorated Portuguese initially breathed new life into the club, winning a cup double in 2017 and securing a runners-up finish in the Premier League in 2018, but his defensive brand of football did not delight fans and his abrasive character, with constant rumours about problems with Paul Pogba, affected the dressing room and results suffered. Mourinho is now at Roma after an unsuccessful stint at Tottenham.
Ole Gunnar Solskjaer (December 2018-November 2021)
P168 W91 D37 L40 Trophies: 0
The former United striker transformed the mood at Old Trafford after initially taking charge on a caretaker basis, winning 14 from 19 games to earn the job permanently. Solskjaer led United to third in 2019-20 and runners-up last season, when they also lost the Europa League final on penalties. There has been clear progress and a much-needed cultural reset at the club, but losses to Liverpool, Manchester City and Watford – 4-1 on Saturday evening – compounded recent poor performances and proved to be the end for the 1999 treble hero.