The rise of the sporting director: How little-known executives have replaced managers as the most important people at football clubs - with the world's biggest teams spending millions to hire the right man from a very narrow pool

In his 26 seasons at the club Sir Alex Ferguson was the undisputed man in charge at Manchester United.

Following in the line of legendary managers before him in the sport - including Brian Clough, Sir Matt Busby and Bill Shankly - the man known to many as 'Fergie' ruled the roost with an iron fist.

Deciding when and how team trained, who was on his backroom staff and which players the club would try and sign, nothing happened at Old Trafford - and its Carrington training ground - without Sir Alex knowing about it.