Some will remember the 13 league titles. Others the five F.A. Cups or the financial growth that turned a club from northern England into an international empire that trades on the New York Stock Exchange. But any list of Manchester United Manager Alex Ferguson’s contributions to the game must surely include the concept of Fergie Time, though it may not be an official part of global soccer’s vernacular.

Publicly coined in the 1990s, Fergie Time refers to that period added to a game by the referee that, should Manchester United be in need of a goal, always seems to drag on long enough for the Red Devils to score and turn the result on its head. Some trace it to a game in 1993 when United received seven minutes of injury time against Sheffield Wednesday and scored a winner to ensure the club’s first top-division championship since 1967, but instances over the years have become part of United’s lore. Depending on one’s point of view, Fergie Time is either maddening or miraculous, exhilarating or exhausting.

It is also a fitting legacy. In many ways, Ferguson’s career — which ended Wednesday as he announced his retirement after more than 26 years in charge at Manchester United — included its own significant portion of Fergie Time. He was initially supposed to retire in 2002 but changed his mind, hung around for another decade and won six more Premier League titles in addition to a European championship.

Finally, though, after the Red Devils secured another title last month, the mercurial Scot decided that he had played on long enough.

“The decision to retire is one that I have thought a great deal about and one that I have not taken lightly,” Ferguson, 71, said in a statement. “It is the right time.”

Tributes, from Britain and far beyond, flowed in throughout the day. Ferguson went to United in 1986, taking over a club that was struggling for a foothold in England, let alone the global stage. He produced his first trophy, an F.A. Cup title, four years later, but it was not until the late 1990s that Ferguson’s club developed into one of the most recognizable brands across all continents.

According to Forbes, Manchester United was the second-highest valued team in the world in 2013 (trailing the Spanish soccer club Real Madrid), and that was the first year since 2004 that United did not hold the top spot.

“In my early years, the backing of the board, and Sir Bobby Charlton, in particular, gave me the confidence and time to build a football club, rather than just a football team,” Ferguson said.

Ferguson’s style — intense, irascible, determined and single-minded — was not always popular with players (who might be dropped from the lineup before a big game) or the news media (who often were chastised for asking questions), but his results were undeniable. After turning tiny Aberdeen, in Scotland, into a force, he won 38 trophies with United, creating a juggernaut that never went more than three seasons without a league title from 1993 until his retirement.

That type of success allowed the club’s owners, the Glazer family, which also owns the N.F.L. Tampa Bay Buccaneers, to float the club on the stock exchange last year and reportedly raise $223 million in only 38 days. In the club’s prospectus, however, one warning to investors stood out from the rest: “Any successor to our current manager may not be as successful as our current manager.”

Considering Ferguson’s tenure, that is hardly a stretch. But now the world will find out how large a void is left by his departure, as well as the one by David Gill, the club’s chief executive, who worked closely with Ferguson to enhance Manchester United’s global brand. Gill had announced that he would step down this summer. High-profile potential replacements for Ferguson have been bandied about for years, with José Mourinho and Pep Guardiola among the more notable names to be linked to the job at various times.

The more likely choice is Everton’s David Moyes, a Scottish compatriot of Ferguson’s who has drawn praise from Ferguson in the past and has a reputation for getting the most out of a tight budget at a Liverpool club where a number of Americans, including Tim Howard and Landon Donovan, have played.

Because it is a publicly traded club, United figures to announce a successor quickly. For now, though, Wednesday was left as a day to praise Ferguson. Cristiano Ronaldo, the superstar midfielder who played for United before moving to Real Madrid, posted a picture of him and Ferguson on Twitter with the message, “Thanks for everything, boss.”

David Beckham, another former United star, said, “I don’t think there is anyone around in football who has had that impact, ever.” And the golfer Rory McIlroy weighed in to say that it was the “end of an era.”

Ferguson’s retirement even crossed political lines and became the dominant story in Britain. Prime Minister David Cameron took time out to comment on it, posting a message on Twitter before a meeting with Secretary of State John Kerry to discuss the situation in Syria. “Sir Alex Ferguson’s achievement at MUFC has been exceptional,” Cameron wrote. He added, referring to his favored club, Aston Villa, “Hopefully his retirement will make life a little easier for my team.”

Ferguson’s final home game with United will be this weekend at Old Trafford. His last game will be May 19, when United travels to West Bromwich Albion. At that point, with another Premier League title long since clinched, he will step into an adviser’s role with the club, clearing the way for his successor.

It will be strange, if only because Ferguson led Manchester United for so long that it sometimes felt as if he might never leave. But now he has, offering yet another reminder that everything has to end at some point. Even Fergie Time.