Sir Alex's Reign: 2006-2011

Even Sir Alex was slightly surprised his emerging team were able to overcome Chelsea in 2006/2007, rating his ninth Barclays Premier League triumph as one of his very best.

A thrilling comeback at Everton, displaying the sort of spirit that has become the hallmark of the boss' sides, set up a first title success in three years with a derby win at Manchester City prompting the deposed champions to form a guard of honour at Stamford Bridge in May. But the Goodison triumph drained the Reds and a 3-2 lead against AC Milan in the Champions League semi-final was surrendered in the second leg.

"I have no hesitation putting the championship win at the top of the tree because, for me at any rate, it was the least expected," conceded the manager. "We had three blank years in the league and a lot of fans seemed to think it was the end of the road but there was rebuilding to do and I am just pleased that we have got our house back in order so speedily." Chelsea exacted some revenge in the first FA Cup final back at Wembley, with Didier Drogba, settling a tight, dour match in extra time, but Sir Alex's thoughts were already focused on another Champions League win. "Don't worry, success in Europe will come," he predicted.

Twelve months later - late into the Moscow night on 21 May, 2008 - another incredible season was completed when Edwin van der Sar saved Nicolas Anelka's spot-kick. The Reds had already been crowned English league champions again, Ryan Giggs fittingly scoring the clincher at Wigan on the final day while equalling Sir Bobby Charlton's all-time appearance record. To become kings of Europe again, the Reds had to edge out Barcelona over two tense semi-finals with Paul Scholes' stunner setting up the date with Chelsea in owner Roman Abramovich's native Russia.

Of course, this was the season when Cristiano Ronaldo confirmed his status as a world-class talent - scoring a remarkable 42 goals including the opener in the Champions League final. There were poignant scenes ahead of the derby with City that marked the 50th anniversary of the Munich disaster - even if the result was a surprise defeat - and two wins over Arsenal at Old Trafford (4-0 in the FA Cup and 2-1 in the league) were among the high points. "Our players have a good future ahead of them and though I will be gone before some of them reach their peak, I want to be part of it," enthused the boss. "It's too exciting to leave it all behind!"

United went close to repeating a domestic and European Double again the following year, only to be undone in the Champions League final by Barcelona, emerging as one of the all-time great teams under Pep Guardiola, in Rome. Domestic superiority, for a third successive year, was underlined not only by a four-point winning margin at the top of the table but also by the breathtaking demolition of Arsenal at the semi-final stage of Europe's premier competition. Ronaldo continued to shine after being convinced by Sir Alex to postpone thoughts of a move to Real Madrid and a goalless draw at Arsenal clinched the title following another vital win at the happy hunting ground that was the JJB (now DW) Stadium.

The Carling Cup also sat proudly in the trophy cabinet despite a reliance on some of the fringe performers in the squad with one of them, Ben Foster, the hero in the penalty shoot-out after a goalless final with Spurs. Meanwhile, the FIFA Club World Cup ensured yet more silverware was on show at Old Trafford, Wayne Rooney hitting the winner against LDU Quito, even if Zenit St Petersburg ruined hopes of landing the UEFA Super Cup by beating the ten-man Reds in Monaco.

The outstanding run in the league came to an end - albeit by only one point - as Carlo Ancelotti's Chelsea did the Double in 2009/2010. Didier Drogba's eventual winner in a key game in M16 in April looked clearly offside and the only goal at Stamford Bridge between the two sides, claimed by John Terry, was also hotly disputed. United refused to give up the trophy without a struggle, Scholes scoring in the dying seconds at City for instance, but a draw at Blackburn was ultimately to prove costly with Chelsea emphatically ending any thoughts of some last-day drama by walloping Wigan 8-0.

There were some painful defeats - at home to League One Leeds in the FA Cup and against an Arjen Robben-inspired Bayern Munich in Europe after Rafael was sent off - but it was all about fine margins as always. At least Wayne Rooney really stepped up to the plate after Ronaldo's summer departure to Madrid for a record £80million, and it was his headed winner at Wembley that at retained the Carling Cup to ensure the season was not to be a trophyless one. So, despite the disappointment against Barcelona, the boss was right to say: "Now we have put our regrets behind us, I've got to say I believe we had a pretty decent season."

Obviously that was the case, even without hindsight, and the feat of moving ahead of Liverpool in terms of league title wins was only delayed by a year. The burning desire to make it 19 and 'knock the Scousers off their perch' as the manager had famously once alluded to, drove the team on to again overtake Chelsea and also see off Arsenal's faltering challenge. Dimitar Berbatov's goalscoring form helped him land a share of the Golden Boot award and, once again, the Reds held their nerve in the run-in.

A 2-1 win at a rocking Old Trafford defeated Chelsea again, after two wins over the Blues in the Champions League, with new boy Javier Hernandez scoring early on and a 1-1 draw at Ewood Park thanks to a Rooney penalty, put United out of sight at the Barclays Premier League summit - ensuring this point was rather different to the one managed against Rovers a year earlier. Overtaking Liverpool's record had been a key goal for the supporters all season but, against the odds for some pundits, the club also progressed all the way to the Champions League final again - for the third time in four glorious seasons.

Barcelona again proved too tough a nut to crack in the final a Wembley but the future looks bright within the ranks after the much-vaunted youth team deservedly lifted the FA Youth Cup following a thrilling run in the prestigious competition. City finished strongly to not only lift the FA Cup after edging out the Reds in an all-Manchester semi-final, but also end up level on points with second-placed Chelsea to deliver a warning of their rapidly-growing threat.

As the manager passes the 25-year landmark in charge of United, it is merely another challenge for him to overcome and he wouldn't have it any other way. Liverpool, Blackburn, Arsenal and Chelsea have all suggested they could be top dogs for a sustained period of time in England, only for Sir Alex to reinvent and reinvigorate his side to reach greater heights. This very week, the boss said: "I've not really reflected on it. All I can say is I'm looking forward to the next 25 years." And so to the next chapter in this compelling story of one of the greatest managers the world has ever seen.

Sir Alex timeline
2006-07: United win the Premier League by six points

2006-07: Chelsea edge the FA Cup final and Milan knock United out of Europe

2007-08: In the 50th year since Munich, the title is retained

2007-08: Shoot-out glory in Moscow as Chelsea are beaten

2008-09: Boss celebrates 50 years in professional football

2008-09: The Reds beat Quito to win the Club World Cup

2008-09: A third Premier League in a row is secured

2008-09: Barcelona defy United in the Champions League final in Rome

2009-10: Sir Alex overtakes Sir Matt as United's longest-serving manager

2009-10: The Carling Cup is won, but Reds lose the title race by a point

2010-11: A record 19th league title is clinched at Blackburn

2010-11: Barcelona again prove a step too far in the Champions League final