Alex Ferguson's shock retirement as Manchester United manager in 2013 meant that the Football Association's 150th year was one of seismic upheaval in the English game.
By the end of the year, United's two-decade reign as English football's dominant force was in serious jeopardy, leaving their rivals scrambling to take advantage.
Jose Mourinho was back at Chelsea, Gareth Bale was no longer a Tottenham Hotspur player, and every Premier League ground was equipped with pioneering goal-line technology.
The year had started in familiar fashion, with United romping to an unprecedented 20th league title, but at 09:17 on the morning of Wednesday, May 8, everything changed.
A tweet published by the United press office confirmed the jaw-dropping rumours that had first emerged on the Daily Telegraph website the previous night: Ferguson, the father of the modern United and the most successful manager in British football history, was stepping down after 26 and a half record-breaking years.
His last home game, an occasion drenched in emotion, saw United beat Swansea City 2-1, before he bowed out with an extraordinary 5-5 draw at West Bromwich Albion in his 1,500th and final match at the helm of United.
The 71-year-old Scot hand-picked his own successor, Everton manager and countryman David Moyes, and urged the club's fans to "stand by our new manager" during his final address to the crowd after the win over Swansea.
Ferguson predicted that there would be difficult times ahead, but there was widespread incredulity at the rapidity of United's decline.
Despite the best efforts of a resurgent Wayne Rooney, who had again seemed close to leaving the club during the close season, United lost five of their first 16 league games to all but relinquish their title.
"The players are hurting, because they are used to winning and when they don't, that hurts," Moyes admitted.
"But they will respond. There is no doubt about that."
A new £5.5 billion ($9 billion, €6.6 billion) television rights package sparked huge investment during the transfer window, with Chelsea and Manchester City spending freely and Spurs re-investing much of the reported world-record £100 million fee that they received for Bale from Real Madrid.
It was Arsenal, however, who emerged as the unexpected early-season pace-setters.
Buoyed by a stunning £42.4 million swoop for Mesut Ozil and inspired by the superb form of Aaron Ramsey, Arsene Wenger's side overcame the shock of a 3-1 home defeat by Aston Villa on the season's opening day to surge to the top of the table.
With United toiling, the chasing pack was headed by Liverpool, free-scoring City and Chelsea, who brought back the charismatic and controversial Mourinho after interim coach Rafael Benitez had led the club to glory in the Europa League.
Luis Suarez found thrilling form for Liverpool after serving a 10-match ban for biting Chelsea's Branislav Ivanovic and his brace in a 5-0 win at Tottenham proved the final straw for Spurs manager Andre Villas-Boas, who was promptly sacked.
The FA celebrated the 150th anniversary of its foundation with a succession of prestige friendlies and England marked the milestone by qualifying for next year's World Cup in Brazil with a 2-0 win over Poland at Wembley Stadium in October.
Optimism was swiftly tempered though, with back-to-back friendly defeats by Chile and Germany followed by a daunting World Cup draw that pitted Roy Hodgson's men against Italy, Uruguay and Costa Rica.
Age-old concerns about English technical deficiencies rumbled on, meanwhile, as new FA chairman Greg Dyke launched a commission to examine how to increase the dwindling number of England-eligible players plying their trade in the Premier League.
Wigan Athletic pulled off a huge upset in the FA Cup final, stunning Manchester City 1-0 through Ben Watson's late header on a rain-soaked afternoon at Wembley and contributing to the dismissal of City manager Roberto Mancini.
Former Real Madrid coach Manuel Pellegrini stepped into the vacancy at the Etihad Stadium, while Roberto Martinez left Wigan - who were subsequently relegated - to succeed Moyes at Everton.
The League Cup went to Swansea, who claimed their maiden trophy with a 5-0 demolition of Bradford City, and there was further success for Welsh football as Cardiff City returned to the top flight after 51 years away.
The Premier League became the first national championship to install goal-line technology, provided by Hawk-eye, but the year ended amid troubling allegations of spot-fixing in the lower leagues.
Whatever 2014 brings, English football will never be the same again.