The manager leaves the supporters with the most incredible memories of scintillating football, great excitement and, of course, a string of trophy successes.
Everybody will have their own favourite game from his reign but we are looking at the matches when the Reds really cut loose and racked up the biggest victories of his tenure.
This week's trivia question is:
Name the six occasions when Sir Alex's United have scored seven times or more in a single game.
Click here for the answer.