Manchester United won the treble during the 1998/1999 season. They actually completed the treble in 1999 on 26 May when they won the UEFA European Cup.
Manchester United have only 1 Treble, winning the Premier League, FA Cup and European Cup, and have done this in 1999.
Manchester United Foot Ball club
They haven't the only club to achieve this are Manchester united.
May 5th 2008Manchester united did not win the champion league in 2008, they last won it in 1999 in Barcelona. That year they won the treble.
Manchester united has no chance to win this year because they are crap! Chelsea or Manchester city will win!
Well ... Manchester United first won the F.A cup in the year 1890!
In 1999, Manchester United won the League title, FA cup and the European Cup (champions league).