After some fanfare, former Manchester United manager has sensationally returned to the Premier League dugout to manage Tottenham Hotspur.
The Portuguese has replaced Mauricio Pochettino as manager and, as ever, his return has split opinion across the footballing world.
He has a great reputation as a proven winner, winning league titles in four different countries but he has left his last three jobs in mutiny and has fallen out with many players over the years.
Mourinho took over from Dutchman, Louis Van Gaal, in 2016, with the aim of taking United to the top of the league.
He had a turbulent spell as Man United manager, becoming the first Reds boss to win a trophy since Sir Alex Ferguson retired, winning the League Cup in 2016, and then the Europa League in the same year to secure Champions League qualification the next season.
Mourinho led United to their highest-placed finish since Ferguson departed in his second season, finishing runners-up, but they finished a distant 19 points behind neighbours Manchester City.
This is when it all fell apart.
The 56-year-old became moody and hostile and made United a boring team to watch.
In his second season, United were given a favourable Champions League tie against Sevilla but Mourinho employed conservative tactics in both matches and they were knocked out, leading many United fans to turn against him.
In the post-match press conference, Mourinho refused to take responsibility as he often does, and said Sevilla had more ‘football heritage’ than the three-times champions of Europe.
His interviews and tactics were often unbecoming for a Man United manager, criticising Marcus Rashford and other young players in public.
He struggled to find a style of play that suited his players and wanted to sit back and defend, despite not having a defence to be able to cope.
He wanted to sit back and play on the counter-attack but his choice of striker, Romelu Lukaku, struggled to hold the ball up.
His abrasive man-management that worked with the likes of John Terry and Frank Lampard, has encountered problems with the modern player and if he is to succeed at Spurs, he will need to adapt and be more sensitive and endearing like Pep Guardiola and Jurgen Klopp.
Mourinho’s third season at United ended predictably in turmoil. He spent the pre-season moaning about the lack of signings and he had a point. Executive vice chairman Ed Woodward did not back him fully and lost trust in him. Mourinho was denied a centre-back which was needed for the club to advance.
However, there was a valid reason for not giving him more money as he spent £370 million and had disappointing results. The former Chelsea manager has a penchant for signing ready-made stars but he failed to get the best out of Henrikh Mkhitaryan, Alexis Sanchez, Fred and Paul Pogba.
Mourinho has won his first two matches at Tottenham and has predictably turned on the charm, but he has a lot to prove and Spurs fans should be wary. He often demands a huge transfer budget and chairman, Daniel Levy is not known to spend big.
The ‘Special One’ does though, inherit a much better side than he did at United. Spurs reached the Champions League final under Pochettino and Mourinho has said he does not need to sign many players because he believes the squad is strong.
Tottenham haven’t won a trophy for more than a decade – the League Cup in 2008 their last success – and Mourinho is as close to a guarantee when it comes to winning domestic cups.
But is that enough?
He has said he has evolved and learned a lot since he left United and he will have had to, because this is probably his last opportunity of managing a big club.