Sir Alex Ferguson is widely considered to be the greatest football manager that has ever lived and it's difficult to argue.
At the helm of Manchester United, the fiery Scot oversaw the rise of global sporting empire that would go on to dominate the Premier League game with merciless ease.
There was no one who could get as much out of a group of players as Fergie could and the glut of titles that flowed throughout his time at Old Trafford just proves that point.
Ferguson's United behemoth would win a staggering 13 titles, and five FA Cups to go with his two Champions League triumphs as well.
They simply are story book numbers that may never be matched again in ours, or any lifetime.
However, it wasn't always glitz and glory for the Scot at United.
His first few years at the club were tumultuous to say the least and, had it been in modern-day football, it is very likely that Fergie would've been shown the door by the United hierarchy.
There were plenty of signs that he was up for a fight in those early years, though, and there perhaps is no moment that better demonstrates it than when a thunderous Ferguson bought himself on as a substitute in the Caribbean.
During a hot-tempered mid-season clash with Guyana, a simmering Ferguson took exception to the way the opposition centre-back was treating his players and decided to take matters into his own hands.
Ferguson bought himself on as a substitute and went full throttle from the get go.
It took just two clashes with the centre-back for Fergie to exact his revenge but, unfortunately, despite the moral victory, the gaffer was given his marching orders by an incandescent referee.
You can read the full story in the tweet below:
Brilliant.
You just won't get this sort of thing happening in modern-day football.
Fergie, now retired and eternally etched across the history of the club, truly was a one-of-a-kind sort of character.
Sadly, we may never see another of his ilk in the Premier League but at least we have the fantastic memories to call on.
On the occasion of his 80th birthday, we can only sit back and propose a toast to the boiling boss who took absolutely no nonsense from anyone.