The 1998-99 season will forever be engraved in Manchester United's history.

It was a truly spectacular season for the Red Devils as they became the first and only side in the history of English football to win the Premier League, FA Cup and Champions League in a single campaign.

There is an argument that the treble should be remembered as Sir Alex Ferguson's finest achievement at the helm and just what occurred during that particular season will go down in football folklore.

Experienced players in the shape of Brian McClair and Gary Pallister had actually left the summer before, but the likes of Jaap Stam, Jesper Blomqvist and Dwight Yorke arrived, and all three were to play important roles for the English giants throughout an incredibly crowded nine months of football.

United actually started the campaign with a 3-0 defeat to Arsenal in the Charity Shield, while they drew their first two Premier League matches against Leicester City and West Ham United. The Red Devils needed two late goals against Leicester to salvage a point on the opening weekend, but they did pick up victories over Charlton Athletic and Coventry City at the start of September.

© Reuters

Ferguson's side overcame Polish champions LKS Lodz in the second qualifying round of the Champions League, meanwhile, to ensure that they would be present in the group stages of the competition. September brought their first two Group D fixtures, and they both ended in draws against Barcelona and Bayern Munich.

United's first league defeat of the season came away to Arsenal on September 20, but they were to win five of their next seven - remaining unbeaten in the process - before suffering their second league defeat of the campaign away to Sheffield Wednesday on November 21.

The Red Devils had been drawn in the so-called 'group of death' in the Champions League, but they recorded back-to-back victories over Brondby - scoring 11 times in the process - to leave themselves in a strong position to qualify ahead of their final two group fixtures away to Barca and at home to Bayern.

Yorke scored twice in a 3-3 draw at Camp Nou on November 25, while a 1-1 draw at home to Bayern on December 9 meant that the club progressed to the quarter-finals of the competition in second spot.

In the league, United only won one of their five matches between November 29 and December 19, suffering a 3-2 loss at home to Middlesbrough before the festive period. At that stage, they were third in the table - their joint-lowest position since the end of September.

A 3-0 victory over Nottingham Forest on December 26 was followed by a goalless draw at Chelsea in their final league game of 1998, but they won each of their next five in the Premier League, including a 6-2 success at Leicester and a famous 8-1 victory away to Nottingham Forest on February 6.

The FA Cup also got underway in January, and Middlesbrough, Liverpool and Fulham were dispatched in round three, four and five respectively to book a sixth-round clash with Chelsea.

A double from Yorke in the sixth-round replay saw Ferguson's side record a 2-0 victory at Stamford Bridge to progress to the semi-finals of the competition, where Arsene Wenger's Arsenal were waiting.

The Gunners halted United's Premier League winning run on February 17 as the two teams played out a 1-1 draw at Old Trafford, but the Red Devils would not be moved from first position, and they then won their next four in England's top flight, with Andy Cole and Yorke continuing to fire.

© Reuters

March brought the return of the Champions League, meanwhile, and a spot in the semi-finals of the competition was secured courtesy of a 3-1 aggregate success over Inter Milan. Indeed, a 2-0 victory at Old Trafford set Ferguson's side up nicely ahead of the away leg at San Siro, which finished 1-1.

United only won one of their three Premier League games in April, drawing with Wimbledon and Leeds United, and they were second in the table heading into May. The month proved to be incredibly successful elsewhere, though, as positions in both the Champions League and FA Cup finals were secured.

The Red Devils needed a late Ryan Giggs equaliser to draw 1-1 with Juventus in the first leg of their Champions League semi-final on April 7, but the English giants were staring at a defeat after just 11 minutes of the second leg two weeks later. Indeed, a double from Filippo Inzaghi had left the Old Lady with a 3-1 advantage, but Roy Keane and Yorke levelled the scores in the 23-minute period that followed, before Cole famously found the back of the net from an acute angle late on to secure a 3-2 victory on the night.

Keane had picked up a yellow card in Italy to rule him out of the final, but a sensational performance from the club captain - arguably his finest-ever outing - inspired his side to book their spot at Camp Nou, where Bayern were waiting to face the English giants for the third time that particular season.

© Reuters

There was also huge drama in the FA Cup as a 0-0 draw between United and Arsenal on April 11 meant that the two sides would meet three days later at Villa Park in a semi-final replay. Peter Schmeichel saved a late Dennis Bergkamp penalty to keep the score at 1-1 heading into extra-time, before Giggs came up with a truly iconic moment - the Welshman embarking on a mazy run, dribbling past four Arsenal defenders in the process, before firing the ball high into the net above a helpless David Seaman to send a 10-man United through.

The match was just another indication of the 'never-say-die' attitude that had been instilled at the club but despite making two finals in April, there was still work for a jaded squad to do in the Premier League.

Arsenal and Chelsea were very much in the mix when it came to the league title but after beating Aston Villa and drawing with Liverpool on May 1 and May 5 respectively, Ferguson's side reclaimed first position in the table with a huge 1-0 success away to Middlesbrough on May 9 - Yorke continuing his stunning form as he made it 29 goals for the season in all competitions.

United needed four points from their final two matches to be sure of the title and one of those came at Ewood Park as they picked up a 0-0 draw, relegating Blackburn Rovers in the process. As a result, the title race went to the final day - Les Ferdinand handed Tottenham a shock lead at Old Trafford, but Beckham levelled the scores in the 43rd minute before Cole scored in the 48th for 2-1.

As it turned out, United needed the win as Arsenal finished with a 1-0 success at Villa, meaning that Ferguson's side finished just one point clear of the Gunners, who were three points clear of Chelsea in third.

© Reuters

Eight days after beating Tottenham, United secured a double by recording a 2-0 win over Newcastle United in the FA Cup final. Less than 10 minutes into the contest, Teddy Sheringham replaced the injured Keane, and the striker opened the scoring in the 11th minute before Paul Scholes netted early in the second period on what was a fairly comfortable afternoon for the English giants.

Just four days later, there was the small matter of the Champions League final. United were without first-choice midfielders Keane and Scholes through suspension, meaning that there were starts for Blomqvist and Nicky Butt. Mario Basler's free kick sent Bayern ahead in the sixth minute of the contest, before Mehmet Scholl and Carsten Jancker both hit the woodwork as the German giants threatened to put the game to bed.

United somehow stayed in touch, though, and the substitutions of Sheringham and Ole Gunnar Solskjaer in the 67th and 81st minute respectively proved to be crucial. Indeed, Sheringham spectacularly levelled the scores in the 91st minute when he made use of a poorly-stuck effort from Giggs, seemingly sending the final into extra time, which would have likely favoured Bayern as Ferguson's side were running on empty.

There was to be no additional 30 minutes, though, as United forced another corner less than 30 seconds after the restart, and Solskjaer reacted fastest to a header from Sheringham to find the back of the net with an instinctive finish, sparking incredible scenes on the United bench and indeed inside the stadium.

Samuel Kuffour and Lothar Matthaus were among the Bayern players left astonished at the final whistle as United had completed an incredible comeback, securing a famous treble in the process. Just 24 hours after the final, almost 500,000 fans lined the streets of Manchester to greet the players, who paraded their trophies.

© Reuters

The Champions League final was to be Schmeichel's last outing for the club, and there is no question that the Dane was vital to the team's success in 1998-99. The same can also be said for Cole and Yorke, who netted 53 goals between them, while Keane and Stam were also both colossal figures for the club.

It was a real squad effort across the board, though, with Solskjaer ending the campaign with 18 goals in all competitions, while Butt, Phil Neville, Blomqvist and Henning Berg were also key contributors as Ferguson was forced to shuffle his pack on a number of occasions.

Incredibly, the classic United XI - Schmeichel; G Neville, Johnsen, Stam, Irwin; Beckham, Keane, Scholes, Giggs; Yorke, Cole - only started one Premier League game together during the 1998-99 Premier League season, which is perhaps the biggest indication of the collective effort that contributed to what was a truly memorable campaign for the most successful side in English football.