The Scot's 26-and-a-half years at Old Trafford are littered with key moments and turning points that have helped forge the 71-year-old's legacy. Here, we look at just 10 of those seminal events.
1990: With Ferguson under pressure after a slow start at Old Trafford, Mark Robins fires United to victory over Nottingham Forest in an FA Cup tie to earn him a stay of execution. The goal is the trigger for a run to the final, where United beat Crystal Palace in a replay to secure the Scot's first silverware.
1992: After missing out on the league title to Leeds in 1991/92, Ferguson responds by signing Eric Cantona for just over £1million from the Yorkshire club. Cantona goes on to help United to four league titles and two FA Cups. 1993: History records Cantona's arrival as the final piece of the puzzle that saw United land the first of the 13 championships amassed during Ferguson's reign at the end of the 1992/93 season.
1995: While Ryan Giggs broke into the first team in 1991, it was not until the 1995/96 campaign that Ferguson felt the full benefit of United's academy programme, with David Beckham, Paul Scholes, Gary and Phil Neville and Nicky Butt all playing key roles in another successful title campaign.
1997: David Gill arrives at Old Trafford as finance director, later rising to the position of deputy chief executive, group chief executive and finally chief executive of Manchester United PLC. Ferguson and Gill formed a strong working partnership and it came as no surprise to many that the two men elected to stand down within months of each other.
1999: The 1998/99 season marked the height of Ferguson's reign, his team of homegrown stars and astute signings, among them the likes of Andy Cole, Teddy Sheringham and Jaap Stam, sweeping all before them in the Premier League and FA Cup before mounting a dramatic late fightback to stun Bayern Munich in the Champions League final.
2001: Ferguson reveals ahead of the 2001/02 season that he plans to retire at the end of the campaign. The uncertainty caused by his announcement gives way a third-placed league finish and failure in the cups. Ferguson later backtracks on his retirement plans, and in later years brands the episode "an absolute disaster".
2005: The Glazer family takeover at Old Trafford creates a rare atmosphere of disharmony, with many fans unhappy at the decision to secure much of the debt against the club's assets. The episode gives Ferguson the opportunity to again display his worth. 2011: A seminal year for Ferguson as he becomes the longest serving manager in United's history - eclipsing Sir Matt Busby - and guides United to a record 19th league title to finally knock Liverpool "off their perch".
2012: A season without a trophy reaches its nadir as United lose the Premier League title to Manchester City on the final day of the season. Ferguson tells his players never to forget how they feel, and they duly respond a year later by reclaiming the crown with four games to spare.
Source: PA
Source: PA