Sir Matt Busby.
Sir Alex Ferguson (2, both as manager for Manchester United) Rafael Benitez (1, as manager for Liverpool) Roy Keane (1, as player of Manchester United)
He was manager of Manchester United from 1971 to 1972
the Manchester united manager is sir Alex Ferguson
Bobby Charlton played for Manchester united, Then he become the Manchester united manager
Sir Alex Ferguson, he has been the manager of Manchester United for 24 years now.
who was manchester united football club manager before Ron Atkinson
Manchester United.
Alex Fergeson, he had won about 39 pl tittles and three champion league tittles.
Ernest Mangnall was the manager at that time then left to mangage manchester city
Bobby Charlton was manager of Manchester United from 1967 to 1973.
manchester united won the league in 2000
This is a matter of opinion but on credentials alone Sir Alex Ferguson (Manchester United) is by far the best.