Manchester will be home to two of the most successful managers in the world next season, as United's Jose Mourinho and City's Pep Guardiola go head-to-head in the Premier League.
The pair have clashed many times before and have a fierce rivalry.
As they warm up for a Premier League battle with a meeting in the International Champions Cup, we look back at their records against each other and the times they've clashed…
Guardiola v Mourinho
|La Liga||Champions League||Copa del Rey||UEFA Super Cup||Spanish Super Cup||Total|
|Draws||1||2||1||1 (PG won on pens)||1||6|
Guardiola's Barcelona v Mourinho's Inter Milan
Four meetings: Guardiola: 2 wins, Draws: 1, Mourinho: 1 win
The first meeting between Guardiola and Mourinho as managers produced a typically intriguing tactical battle, as Barcelona and Inter Milan played out a 0-0 draw in a Champions League group game at the San Siro in 2009.
The reverse fixture, though, saw the Spanish side win a one-sided contest 2-0 at the Nou Camp. The hosts were without Lionel Messi or Zlatan Ibrahimovic but Xavi picked Mourinho's men apart.
After the game, Mourinho conceded his team had been outplayed - but welcomed the chance of another crack at Guardiola's team: "We're far from being Barca in terms of individual qualities and profile. As a team, Barcelona are better than us. But if I had to play against Barca again tomorrow, I would already be ready. If you told me that Inter will face Barca in the semi-final, I will accept it already."
Jose Mourinho and Pep Guardiola worked together at Barcelona between 1996-2000, when Mourinho was a coach and Guardiola was a player.
Mourinho got his wish. Inter did come up against Barcelona in the semi-finals - and this time they emerged victorious. However, in a glimpse of how Mourinho and Guardiola's rivalry would develop, the tie was not without its controversy or outspoken remarks.
After a first-leg 3-1 win at the San Siro for the Italian side, Mourinho slammed Barca's claims they should have had a penalty for a foul on Dani Alves.
"A year ago Chelsea were crying and Barca were laughing with the referee," Mourinho said, referring to the controversial Champions League semi-final at Stamford Bridge, which saw referee Tom Henning Ovrebo reject a number of penalty claims from the Blues. "They laughed because he denied my Chelsea boys their rightful place."
Mourinho was even more impassioned after his side - reduced to 10 men midway through the first-half - booked their final berth with a 1-0 defeat in Barcelona.
"It is the most beautiful defeat of my life," he said. "It is a style of blood not skill. We were a team of heroes. It's a pity I could not play because I have got the same blood. I have already won a Champions League but today was even better. We made huge sacrifices."
Mourinho's Inter would go on to win the Champions League and match Barcelona's 2008/09 achievement of winning a treble.
Guardiola v Mourinho - trophies
|2 Champions Leagues||2 Champions Leagues|
|3 Club World Cups||1 UEFA Cup|
|3 La Ligas||3 Premier Leagues|
|3 Spanish Super Cups||1 FA Cup|
|3 UEFA Super Cups||3 League Cups|
|2 Copa del Reys||1 Community Shield|
|3 Bundesligas||2 Serie As|
|2 German Cups||1 Coppa Italia|
|1 Italian Super Cup|
|1 La Liga|
|1 Copa del Rey|
|1 Spanish Super Cup|
|2 Portuguese Leagues|
|1 Portuguese Cup|
|1 Portuguese Super Cup|
|Total: 21||Total: 22|
Guardiola's Barcelona v Mourinho's Real Madrid
Eleven meetings: Guardiola wins: 5, Draws: 4, Mourinho wins: 2
The rivalry between Guardiola and Mourinho hit a whole new level in 2010, when Mourinho was appointed Real Madrid boss. During the next two seasons, as the pair vied for domestic and European honours, their relationship turned ugly.
A thumping 5-0 win for Guardiola in Mourinho's first El Clasico handed the Spaniard a head-start. "I'm proud the whole world has seen how we play football," he said.
But it would be a run of four meetings in a little over two weeks from mid-April, as Barcelona and Real Madrid clashed in La Liga, the Copa del Rey and Champions League, which saw the pressure get to both men.
There was a penalty for each team as a 1-1 draw at the Bernabeu all-but assured Barcelona of the league title. But Cristiano Ronaldo clinched the Copa del Rey in extra-time four days later, ending Real's 18-year wait to lift the Spanish cup.
After the game Guardiola sparked a war of words by suggesting the linesman must have had great eyesight to spot Barcelona's Pedro was in an offside position before scoring what would have been the opening goal.
"Up until now there was a very small group of coaches who didn't talk about referees and a larger group who did," said Mourinho ahead of the teams' Champions League semi-final first-leg. "Now, with Pep's comments, we have started a new era with a third group, featuring only one person, a man who criticises [the referee] when he makes good decisions. This is completely new to me."
Guardiola was incensed - and hit back. "As senor Mourinho has called me Pep, I'm going to call him Jose," he said in his pre-match press conference. "Tomorrow at 8.45pm we will face each other on the pitch. Off the pitch he's won. He's been winning off the pitch all season. Let them give him a Champions League for it so he can enjoy it and take it home. In the press room he is 'el p*** jefe' (the ******* boss) and the one who knows more than everyone else."
Off the pitch he's won. Let them give him a Champions League for it.
The Barcelona manager reportedly returned to the team hotel to a standing ovation from his players, who went on to win the first leg of the Champions League semi-final 2-0 at the Bernabeu with two late goals from Messi.
For the fifth game in a row (including Inter Milan) Mourinho had a player sent off against a Guardiola side. Pepe was shown a red on 61 minutes and Mourinho himself was dismissed for protesting.
After the match, he launched a shocking attack on Barcelona and the integrity of UEFA officials. "One day, I would like Josep Guardiola to win this competition properly," he said.
"If I tell UEFA what I really think and feel, my career would end now. Instead I will just ask a question to which I hope one day to get a response: Why? Why Ovrebo? Why Busacca? Why De Bleeckere? Why Stark?" he continued, naming the referee who officiated Chelsea's exit the previous season and the three referees to have taken charge of Mourinho's most recent matches with Guardiola.
"Why? Because every semi-final the same things happen. We are talking about an absolutely fantastic football team, so why do they need that? Why? Why does a team as good as they are need something [extra] that is so obvious that everyone sees it?
"I don't know if it is the UNICEF sponsorship or if it is because they are nice guys. I don't understand. They have power and we have no chance. All I can do is leave that question here in the air and hope that one day I will get the response. They have to get to the final, and they'll get there, full stop.
I would be ashamed to have won the Champions League with the scandal of Stamford Bridge. If he wins it this year, it will be with the scandal of the Bernabeu.
"Josep Guardiola is a fantastic coach. But I have won two Champions Leagues and he has won [only] one Champions League - and that is one that would embarrass me. I would be ashamed to have won it with the scandal of Stamford Bridge. If he wins it this year, it will be with the scandal of the Bernabeu. Deep down, if they are good people, it cannot taste right for them. I hope one day Guardiola has the chance of winning a brilliant, clean championship with no scandal."
With Mourinho serving a touchline ban the sides drew 1-1 at the Nou Camp, sealing Barcelona's passage to the final. "This has been one of the most beautiful nights I have ever lived," said Guardiola, whose team would go on to beat Manchester United at Wembley.
Any hopes the off-season would allow Mourinho and Guardiola's rivalry to cool off vanished in the midst of a fierce Spanish Super Cup second-leg the following August.
After drawing the first match 2-2 ugly scenes marred the return in Barcelona, with Mourinho poking Tito Vilanova, Guardiola's assistant, in the eye during a melee which followed a ferocious tackle from Marcelo on Cesc Fabregas.
The Real Madrid manager was also seen making gestures towards Messi and Alves and, after the 3-2 defeat, criticised the hosts' ball boys. "Someone has to take action on the matter. Mourinho is destroying Spanish football," said a furious Gerard Pique, the Barcelona defender.
Mourinho, though, was ready for war. "I'm not going to say we're happy because we didn't win the Spanish Super Cup, that would be hypocritical of me. But we intended to play like men and not fall on the ground at the slightest touch. I have been taught to play like a man and not to fall first."
However, Guardiola would once again get the better of Mourinho in the first league clash of the season, pulling level with their rivals at the top of La Liga after bouncing back from the quickest-ever Clasico goal from Karim Benzema to win 3-1.
A little over a month later Barcelona were victorious again at the Bernabeu, taking a 2-1 Copa del Rey first-leg lead back to the Nou Camp, where they booked a semi-final spot in the competition they'd go on to win.
However, despite defeat to Barcelona in December, Real Madrid were proving an unstoppable force for all other comers in La Liga, winning 11 in a row after that Clasico loss. By the time they went to the Nou Camp in April, the title was in their hands - and Ronaldo hit the decisive strike in a 2-1 success to put Real seven points clear with four games remaining.
It was Barcelona's first home defeat in 55 games, Real's first Clasico win since 2008 and their first at the Nou Camp for five years. "We can't expect to always be up to the standard but it's a pity we faltered in the decisive moment," rued Guardiola. Mourinho declined to speak to the press.
Real went on to win all four remaining games to take the title for the first time in four years, finishing with a record 121 goals to their name and a nine-point advantage over Barcelona. As an illustration of how far clear Mourinho and Guardiola's men were of the rest, third-placed Valencia were 39 points off the summit.
At the end of the season Guardiola announced he was leaving Barcelona for a sabbatical. "It's his life, but for me it's unthinkable to take a sabbatical. He is younger than me, but I'm not tired," was Mourinho's farewell.
Guardiola's Bayern Munich v Mourinho's Chelsea
One meeting: One draw (Guardiola won on penalties)
Guardiola and Mourinho resumed their rivalry in August 2013, when Bayern Munich and Chelsea met in the UEFA Super Cup. Neither man had won the Champions League or Europa League with those respective clubs the previous season but Guardiola, fresh from his year-long sabbatical, and Mourinho, back at the Bridge after leaving Real Madrid, were eager to kick-off their new jobs in style.
Guardiola had taken charge of Jupp Heynckes treble-winning Bayern but needed a last-gasp Javi Martinez equaliser in extra-time against 10-man Chelsea to take the game to penalties. The Spaniard then delivered an inspiring team talk to his players, according to Pep Confidential, Marti Perarnau's book on Guardiola's first season at Bayern.
"Firstly, make up your mind immediately as to where you're going to put the ball and stick with that decision," Guardiola said. "I'll say it again. Decide now, and don't change your mind no matter what happens. Secondly, keep telling yourselves that you're going to score. Repeat it a thousand times and don't stop until after you've taken the penalty. Don't worry and don't change your minds."
The instructions worked. Bayern won the Super Cup, and Guardiola scored victory over his long-time rival. "The best team clearly lost," retorted Mourinho. "They just scored one more penalty."
After the game, Mourinho was quizzed by the press on his poor record against Guardiola - he had only won three of their 16 meetings.
"Your statistics are wrong and very wrong," Mourinho said. "Go there and see what happened with Inter in the Champions League semi-final. I won the Spanish cup final in Valencia, I won the Super Cup in Spain. I was champion in Spain. I won the match for the title in Barcelona with Real Madrid."
Pushed on whether Mourinho had more accurate statistics, he said: "I don't know. Maybe you are right and I am wrong. But I don't care. It's not important."
Expect both managers to show just how important their rivalry is to them when United and City and meet in 2016/17. The pre-season 'friendly' between the clubs on 26 July in China will be an interesting clash on and off the pitch.