Man Utd's top 10 transfer windows ranked: From stealing Robin van Persie away from Arsenal to building a treble-winning team

Despite winning three consecutive titles, United were not prepared to stand still. Having been on the verge of signing Ruud van Nistelrooy the previous summer until a knee injury wrecked the move, United completed a £19m (£24) move for the Dutch striker.

As if landing the prolific forward wasn't enough, they then made Juan Sebastian Veron their record signing for £28m ($35m). Where United went wrong that summer was to sell Jaap Stam - albeit for a tidy £16m ($20m) - and to replace him with the 35-year-old Laurent Blanc.

United lost the title the next season to Arsenal, painfully surrendering their crown after defeat by the Gunners at Old Trafford. But they reclaimed it the following season and Van Nistelrooy, who had also had a stunning first campaign, finished as top scorer with 25 goals. Veron was inconsistent but also played his part in winning back the title, scoring in the 2-0 win over Arsenal at Old Trafford.

The Argentine had an ultimately unsuccessful two years at United and was sold to Chelsea for £14m ($18m) in the summer of 2003 but Van Nistelrooy remains one of the club's greatest ever strikers, scoring 150 goals in his five seasons.

United had hoped to sign Alan Shearer this summer but the England striker ultimately wanted to go back to boyhood club Newcastle, United's main rivals at the time. The Red Devils saved £15m ($19m) by missing out on Shearer and instead bought a number of relatively unknown foreign players.

Karel Poborsky was the most famous after scoring a stunning chip in Euro 1996, while Jordi Cruyff was best known for being the son of legendary player Johan. But the most successful signings were the two Norwegians, Ronny Johnsen and Ole Gunnar Solskjaer, who cost a combined £2.7m ($3.4m)

Johnsen was a defensive pillar for five seasons and was remarkably consistent, the perfect partner for Jaap Stam. And Solskjaer spent 11 years with United, scoring 126 goals, including perhaps the most important in the club's history, snatching victory over Bayern Munich in the 1999 Champions League final to complete the treble.

At the time, it seemed like madness. United had just lost the league title to Blackburn and been beaten in the FA Cup final to Everton yet the club made no signings at all. And they decided to sell three senior players, Andrei Kanchelskis and Paul Ince.

The season got off to an awful start as a remarkably young and inexperienced side were beaten 3-1 by Aston Villa on the opening day, prompting Alan Hansen to infamously remarking "You'll win nothing with kids."

Ferguson, however, had a plan. He knew his wonderful generation of young players were just approaching maturity and that Eric Cantona would soon return from his long ban for kung-fu kicking a Crystal Palace fan.

The Frenchman announced his comeback with a penalty against Liverpool and duly inspired United to a league-and-FA Cup double, helped by David Beckham, Paul Scholes, Nicky Butt and the Neville brothers, who had all just come of age.

After a quiet summer transfer window in which they had signed Edwin van der Sar and Park Ji-sung, United went into the market again in the winter. They signed two relatively unknown defenders, Spartak Moscow's Nemanja Vidic and Monaco's Patrice Evra, for a combined £12m ($15m). Neither arrival stirred up any great excitement among fans and they did not get off to the finest of starts.

Evra's debut was the 3-1 defeat at Manchester City while Vidic played in the demoralising 3-0 defeat at Chelsea which saw the Blues clinch the title. But these first few months helped the players adapt to their new surroundings and when the new season began, they had already settled and they hit the ground running.

Vidic and Evra formed part of United's defence for the next eight years, winning practically every trophy imaginable (only the FA Cup evaded their grasp). Signing them up for so little was a fine piece of business.

United had just missed out on the title in agonising circumstances to Manchester City, losing out on goal difference to their "noisy neighbours". And the main difference between the two sides seemed to be their power up front. City could count upon Sergio Aguero, Mario Balotelli, Edin Dzeko and Carlos Tevez, while United's options were Javier Hernandez, Wayne Rooney and Danny Welbeck.

It was clear that they needed a proper striker and took advantage of the fact that Robin van Persie had one year left on his contract with Arsenal to land the previous season's Golden Boot winner (30 goals) for £24m ($30m).

It might have been an obvious move but it paid off handsomely. Van Persie finished as the league's top goalscorer for the second successive season by scoring 24 times and United reclaimed their title in emphatic fashion, wrapping up the title in April thanks to a hat-trick from the Dutchman in a 3-0 win over Aston Villa which featured a famous first-time volley from a long ball forward from Rooney.

The summer also saw the arrival of Shinji Kagawa, who had been one of the key players in Jurgen Klopp's double-title winning Borussia Dortmund. Unfortunately, the Japan international never quite clicked at United, although he did have one match to remember, scoring a hat-trick against Norwich.

United needed to act in the transfer market after their worst season in 30 years of the Premier League. And they had a new manager in Erik ten Hag who needed support. The Dutchman's first two signings, Christian Eriksen and Lisandro Martinez, had made an underwhelming start, though, and after the 4-0 drubbing at Brentford, United knew they had to strengthen again.

Getting five-time Champions League winner Casemiro from Real Madrid was a stunning coup that nobody saw coming. The Brazilian cost a hefty £60m ($76m) but his arrival gave the midfield a long-overdue shake-up.

Eriksen also ultimately proved a shrewd addition on a free transfer, while Martinez has gone on to revolutionise the defence and silence the critics who said he was too small to play in the Premier League.

The only negative of a busy window was Antony. His transfer fee ballooned up to £85m ($108m) and he finished his first campaign with only four goals and two assists in the Premier League. However, he is only 23 and has plenty of time to improve and further settle into the team.

United certainly spent big last year but the outlay helped deliver a first trophy in six years and ensured the team returned to the Champions League.

This was a summer of change at Old Trafford as the club waved goodbye to loyal servants such as Denis Irwin, Ronny Johnsen and Dwight Yorke. There was only one major new arrival but it was a big one: Rio Ferdinand for £30m ($38m), a world record for a defender.

Ferdinand, who was 23 at the time and coming off the back of a brilliant World Cup campaign with England, was a huge upgrade on Laurent Blanc. He made United far more solid and added a new dimension to the team with his ability to step out from defence and link up with midfield - a rare attribute for defenders at the time.

Ferdinand helped United win the title at the first time of asking, although he suffered a big setback the following season when he was banned for eight months for missing a drugs test.

But he eventually formed a wonderful partnership with Nemanja Vidic and is now remembered as one of the club's greatest ever defenders, spending 14 seasons at United and winning six Premier League titles and the 2008 Champions League.

The only other arrival that season was Spanish goalkeeper Ricardo, who played only a handful of matches.

Wayne Rooney was the star of Euro 2004 and it was clear he was going to be the best English player for many years to come. So, United naturally decided that they simply had to have him. They struck a £27m ($34m) deal with Everton, which was a record fee for a teenager. But looking at what he achieved with United, it looks like a bargain today.

Rooney stayed with United for 13 years, lifting a total of 16 trophies. And he became their all-time top scorer on 253 goals, surpassing Bobby Charlton's record which had stood for more than four decades.

Rooney was not the only player to join United that summer. Gabriel Heinze joined from Paris Saint-Germain for £7m ($9m) and was a cult hero among fans until he decided he wanted to join Liverpool, provoking the wrath of Ferguson, who sold him to Real Madrid instead.

Alan Smith, also costing £7m ($9m), joined from rivals Leeds but never quite proved himself at the club, although his hopes of doing so were undeniably undermined by a horrible leg break in 2006. The signing of Gerard Pique from Barcelona was an astute move, although United failed to see the defender's true talent and let him slip back to Barca in 2008 for just £5m ($6m), which would prove to be a gross oversight from Ferguson.

United had just reclaimed the league title for the first time in four years but while they had a thrillingly talented side, they lacked squad depth. Their 3-0 defeat to AC Milan in the Champions League semi-final also underlined the need for more experience and to be more versatile. The club had rested on their laurels before after winning titles and Alex Ferguson and chief executive David Gill knew they had to build on their success, not pat themselves on the back.

Gill signed Anderson, the player of the tournament at the under-17 World Championship two years previously, and Nani in one highly productive trip to Portugal for a combined £35m ($44m). They were bets on the future though so they also signed experience, a Champions League winner in Owen Hargreaves for £17m ($21m) and got Carlos Tevez, who had single-handedly kept West Ham up the previous season, on a two-year loan for £10m ($12m).

Every signing was a success in the first season at least and all played in the Champions League final win over Chelsea in Moscow, with all four scoring in the penalty shootout. In the long term, though, not everything turned out as planned: Hargreaves ended up being plagued by injury, Tevez betrayed the club by moving to Manchester City and Anderson declined.

But they all had excellent first seasons and did what they had been asked to do, helping United see off Chelsea to retain the title and beat the Blues in the Champions League final. Fittingly, all four summer signings scored in the penalty shootout in Moscow.

How do you come back from losing your crown to a daring, vibrant Arsenal side managed by an avant-garde Frenchman? By signing a hard-as-nails Dutch centre-back, a creative yet prolific striker and cover for Ryan Giggs, of course. Signing Jaap Stam, Dwight Yorke and Jesper Blomqvist in one window was incredible business and not just because it led to United sweeping to a historic treble the following season. Stam and Yorke had great careers and contributed to three consecutive titles.

United's morale was on the floor after surrendering the title by blowing a 12-point lead over Arsenal with three months to spare. It was clear investment was needed across the squad and United put their hand in their pockets.

Stam joined from PSV Eindhoven for £10m ($12m) and was worth every penny, his towering presence helping United win three titles on the trot. And when he was sold to Lazio in 2001, Ferguson called it his greatest ever mistake.

The manager also sought to reduce United's dependency on Giggs, signing Swedish winger Blomqvist for £4m ($5m). He was a useful back-up for Giggs in his first season but his own injuries meant he had only had one campaign with the club.

The final piece of the jigsaw was Yorke, whom United had to battle to sign from Aston Villa for £12m ($15m). Yorke scored 53 goals in his first two seasons as well as contributing 25 assists, many of them for his close friend and ideal strike partner Andy Cole.