His autobiography is released today, so what lessons can we draw from this sporting icon?
When Manchester United boss Sir Alex – the most successful manager of a British soccer team in decades – announced his retirement back in May, it generated more than 1.4 million Twitter mentions within the first hour. This ranked as more significant than the death of Margaret Thatcher, if slightly less so than the announcement of the new Pope.
So here are Sir Alex's seven leadership lessons:
