Video report by Chris Hall
Sir Matt Busby, Bill Shankly and Jock Stein all made history at their respective clubs of Manchester United, Liverpool and Celtic.
A new film released this weekend called 'The Three Kings' looks at how their upbringing shaped that success - all three managers were born within 30 miles of each other in Glasglow.
Despite Shankly and Busby managing arch-rival clubs, they shared a great friendship.
Both men are synonymous with building Liverpool and Manchester United into successful football clubs, with both managers guiding their teams to European and domestic trophies.