Sir Alex's men achieved their sixth Premiership title early, in April, and still without a convincing replacement for Peter Schmeichel. A host of goalkeepers, including Mark Bosnich, tried and failed to establish themselves during the 1999/2000 season. So it was hardly surprising when World Cup and European Championship winner Fabien Barthez joined United in July 2000.
The eccentric but formidable French goalkeeper helped United to win a third successive title in 2000/01, a feat that had previously been achieved by only a handful of clubs in England. Liverpool had been the last team to do it, in 1982, 1983 and 1984, but this was under the supervision of two different managers - Bob Paisley and Joe Fagan.
Sir Alex had been at the helm for all three of United's back-to-back titles, and was the first manager in English football to achieve the hat-trick. On the back of this latest trophy, he announced his impending retirement, only to thankfully change his mind and decide to stay.
Ferguson's major signing in the summer of 2002 was Rio Ferdinand, one of England's best performers at the World Cup finals in Japan and Korea. The £30m acquisition from Leeds added the steel that had arguably been missing from United's defence since the departure of Jaap Stam to Lazio.
Ferdinand helped the Reds to recapture the Premiership title in May 2003, a season that marked the departure of one of United’s favourite sons. David Beckham left his longtime home by signing for Real Madrid but his career as a Red ended on a high, scoring a trademark free-kick against Everton in his final game.
Arsenal reclaimed the League title in 2004 but the Reds won the FA Cup for an 11th time, beating Millwall 3-0 in the 2004 final at Cardiff's Millennium Stadium. A year later, United were back in Wales to face Arsenal for the trophy. Chelsea had taken the Premiership and League Cup, and it was the Gunners who triumphed on penalties despite a dominant display from United - for whom Wayne Rooney and Cristiano Ronaldo were outstanding. The following season brought maiden silverware for the pair as the Reds beat Wigan Athletic in the League Cup final.
For Sir Alex and his players, the main aim remained Premier League glory, which was duly snared the following season as United notched a 16th League title, finishing six points clear of reigning champions Chelsea. While the whole squad performed admirably to snatch the title back from Stamford Bridge, the man who took most of the plaudits was Ronaldo, who collected 13 personal honours during the campaign - including the PFA Player and Young Player of the Year award.
While it seemed improbable that the winger could top his 2006/07 heroics, he did just that the following season. Ronaldo played a major part - scoring 42 goals - as the Reds saw off the challenge of Chelsea in the two biggest competitions going. Strengthened by the summer signings of Owen Hargreaves, Carlos Tevez, Anderson and Nani, United recovered from a slow start to the season to head the table for almost the entire campaign. Despite a late charge from Chelsea, a final-day victory at Wigan (in which Ryan Giggs scored the clinching goal on the day he equalled the club's all-time appearances record) secured a 17th league title for United.
Ten days later, in Moscow, the Reds and Blues duked it out for silverware again as two English clubs met in the final of the Champions League or European Cup for the first time. Ronaldo's opener was cancelled out by Frank Lampard and, after 120 tense minutes, the match went to penalties. Ronaldo's miss gave John Terry the chance to take the trophy, but the Chelsea skipper slipped and smacked his effort against a post. Reprieved, United went on to win the shootout when Edwin van der Sar saved Nicolas Anelka's effort, ensuring that Europe's biggest competition had been won by the men from Manchester for a third time.
How do you top a season like 2007/08? Well, Sir Alex's men did their very best and only defeat at the very last hurdle - against Barcelona in the Champions League final - prevented the Reds from a historic trophy haul. Despite ultimate disappointment in Europe, United dominated almost every other competition. In December, the Reds flew to Japan to compete in the FIFA Club World Cup and a solitary Rooney goal against Ecuador's Liga de Quito in the final was enough to crown United world champions.
But what sort of effect would a gruelling mid-season trip to the Far East have on the Reds' domestic aspirations? As it turned out, it only made United stronger: Sir Alex's men reeled in Liverpool (seven points clear when the Reds returned from Japan) before going on to win a record-equalling 18th League title. But even before Gary Neville lifted the Barclays Premier League trophy, the Reds had tasted success against Tottenham in the League Cup. On that occasion, goalkeeper Ben Foster was the penalty shootout hero after the scores remained level after 120 minutes. The Reds ended the decade having lifted a remarkable 14 trophies.