The story of how Leeds United's young charges took Europe's best apart in the Champions League

The realisation of the size of Leeds United's task will have dawned on David O'Leary as he emerged from the away dressing room at the Nou Camp in Barcelona.

The Irishman - who had guided Leeds past 1860 Munich in the qualifying round just weeks earlier - had watched on helplessly as his young Whites outfit was humbled at the hands of the Catalan giants.

Goals from Rivaldo, Frank de Boer and a double from forward Patrick Kluivert left Leeds at the bottom of what appeared to be an unscalable Group H mountain in the 2000/01 edition of the Champions League.

As O'Leary stood in front of the television cameras ready to answer questions, thoughts quickly turned to another mammoth task: the visit of now seven-time European Cup winners AC Milan to Elland Road six days later.

"If somebody had said to me in August in Munich, after we won to go through, that we'd be in the semi-final in May time, no, I'd have found that very, very hard to believe," O'Leary recalled recently.

The story of how Leeds United went from blushing Champions League new boys to tearful beaten semi-finalists is a memorable one - and a tale that is never likely to be forgotten by those who witnessed, or lived it.

“I don’t think there were expectations, we didn’t put those on ourselves,” Whites cult hero Dominic Matteo told the YEP.

“When you see the teams we had to play against, we had it pretty hard right throughout the tournament.

“It was like we were on a magical mystery tour with the Leeds fans, going around Europe, beating teams, just managing to get through, getting results. It was incredible."

O'Leary was right to be worried about the visit of AC Milan to West Yorkshire.

The Serie A side boasted the capabilities of Andriy Shevchenko up front, Paolo Maldini at the back and Brazilian goalkeeper Dida between the posts.

Leeds, though, had a young side who were out to prove a point and it was marauding midfielder Lee Bowyer who did so.

As the driving rain fell, a speculative effort two minutes from time evaded the clutches of Dida, a goal which saw the roof blown off by the 35,000 or so in attendance.

United were on their way and a nine-month story as the talk of Europe was about to unfold before the club's very eyes.

Flanked by full-backs Danny Mills and Ian Harte with trusted stopper Nigel Martyn as the last line of defence, Leeds later broke the bank to add England international Rio Ferdinand to the line-up alongside Jonathan Woodgate and club captain Lucas Radebe in the middle.

Alan Smith and Mark Viduka proved a partnership that would torment defences as Eirik Bakke, Olivier Dacourt, David Batty and Dominic Matteo took it in turns in the engine room.

Leeds had problems off the pitch, in the form of Bowyer and Woodgate, but on it O'Leary had gathered a side who did not flinch over anyone who stood in their way, and it showed.

Besiktas were demolished 6-0 in LS11 before a disappointing 0-0 draw in Istanbul followed in the reverse fixture.

O'Leary's young charges then came within seconds of claiming a historic victory against Barcelona on home soil, but Rivaldo's injury-time strike broke Leeds hearts and left United needing a point at the San Siro to qualify for the second group phase.

Matteo's header in Italy saw him pencil his name in the history books as it eventually sent Leeds through to the next stage, with a 1-1 draw. United's players were left dancing on the pitch. Supporters were left rubbing their eyes in the stands.

Leeds continued to defy expectations, having been drawn with Real Madrid, Lazio and Anderlecht for the next phase.

The Galacticos came and went as they bagged two goals in as many minutes at Elland Road. United, though, secured another historic win as Smith struck 10 minutes from time in Rome.

Two wins against Anderlecht followed, the latter a stunning 4-1 victory which left supporters wondering when they'd wake from their European dream.

A controversial defeat at the Bernabeu and a thrilling 3-3 draw with Lazio after knockout football was confirmed brought Leeds to Deportivo La Coruna's door.

The Spanish side were heavy favourites for the quarter-final clash, so much so the reigning La Liga champions described their foes as the "weakest link" left in competition.

Harte, Smith and a powerful header from Ferdinand saw Leeds put their counterparts to the sword. "Three-nil to the weakest link," Elland Road chanted.

O'Leary's men had defied expectations once more.

A tense away leg followed, as Deportivo scored early from the spot and again with 17 minutes to go. Leeds, like always, found a battling way to win.

Another hurdle passed and another step forward on the unlikeliest of Champions League journeys. Valencia was all that separated Leeds from a fabled European cup final.

"Even if we went out to Valencia, we can still hold our heads high and say we went the furthest of all the Premier League sides," O'Leary proclaimed.

"And it has not been through luck either, because we have beaten a lot of very good teams to get where we are."

Leeds battled, but the two sides headed to the Mestalla goalless and it was there where the journey would end. Perhaps fittingly, and in keeping with history, United conceded a goal that should have never been given.

Juan Sanchez opened the scoring by using his arm to turn home the ball, and Leeds never recovered. It was one setback too many for O'Leary's men as the Whites fell to a 3-0 defeat.

Tears were shed but memories were made. It was United against Europe, a Leeds dream that would be relived and retold for decades to come.