1986 was a monumental year for Manchester United. It was the year when a fiery Scotsman named Alex Ferguson took over the reins as manager, a man who, in time, would go on to become the most successful manager in the history of English football.

Along the way, as Sir Alex's juggernaut kept rolling and the Scotsman kept adding to the trophy cabinet at Old Trafford, a few challengers emerged on the horizon to threaten his supremacy in the English top flight.

Arsene Wenger

Wenger took over at Arsenal in 1996 and, in only his second season, he won both the Premier League and the FA Cup and halted Sir Alex’s run to a fifth title. Having served an 18-month stint in Japan at Nagoya Grampus Eight prior to joining Arsenal, Wenger had limited credentials to his name and not many would have looked on him as a potential challenger to Ferguson.

Over the years, Fergie and Wenger have engaged in many a verbal joust and it has been a rivalry that both men seemed to thrive on. While I am sure that both have respect for each other’s achievements, they seldom lost an opportunity to take a swipe at each other. The rivalry reached its pinnacle when United ended Arsenal’s unbeaten run of 49 games, leading to the notorious “Pizzagate”  incident at Old Trafford.

However, in terms of the trophy tally, Wenger has managed only three league titles and four FA Cups against 10 titles, five FA Cups and two Champions League trophies won by Ferguson.

Jose Mourinho

The next big rivalry was when the “Special One” landed in London and took over at Chelsea in 2004. Having beaten Ferguson in Europe the year before when he led Porto to the Champions League trophy in 2003-04, Mourinho arrived in England with a big reputation and an even bigger ego.

With a few blank cheques at his disposal and a transfer budget bankrolled by Roman Abramovich, Mourinho went on a shopping spree and spent about £70million on players. He went on to secure the first domestic title for Chelsea in 50 years and followed it up with a second in 2005-06.

Mourinho’s ascent in the hierarchy of successful managers in the Premier League, combined with a difficult phase at Manchester United, led people to believe that, finally, there was a man who had out-bought and out-manoeuvred Ferguson.

Football pundits opined that the decline at United was indicative of Fergie losing the plot and that it was time for new ideas and new leadership. United failed to qualify for the knockout phase of the Champions League and finished second in the Premier League, way behind winners Chelsea.

But Ferguson was made of sterner stuff and went on not only to regain the league title in 2006-07 but also successfully defend it in 2007-08, while Mourinho departed Stamford Bridge after falling out with Abramovich.

Luiz Felipe Scolari

The latest chapter in this managerial power struggle is about to be written with Scolari taking over at Chelsea. Thge Brazilian has already drawn the battle lines by allegedly telling Cristiano Ronaldo that Real Madrid should be his preferred destination, a comment that would have undoubtedly infuriated Ferguson.

If Ronaldo pays heed to Big Phil's comments, then Scolari will have, in one fell swoop, removed the most potent attacking force of his adversary. More recently, Carlos Queiroz, Ferguson’s right-hand man, has been offered the role of managing the Portuguese national team, the job vacated by Scolari.

Given Scolari’s temper, penchant for histrionics and a no-holds-barred attitude, we should expect a few feisty battles between him and the Scotsman. It is expected that Scolari will bring more flair to Chelsea. The purchase of Deco is indicative of his intent on attractive, attacking football. With Abramovich expected to splash out cash for a fresh round of acquisitions, the Chelsea team might have a new look about it.

Only time will tell if Scolari is just another pretender to Fergie’s crown or if he's the real deal.