Old rivals Antonio Conte and Jose Mourinho will come face-to-face once more next season.
Mourinho did not stay out of the spotlight for long after his sacking by Tottenham and has been confirmed as the new Roma head coach.
He will join the club ahead of the 2021-22 season on a three-year deal to compete in a league where Conte and his former club Inter have just ended a historic run of Juventus domestic dominance.
A bitter war of words erupted between the high-profile bosses when they were at Manchester United and Chelsea respectively in the Premier League.
Tensions had simmered between the pair since Conte's appointment as Mourinho's long-term successor at Stamford Bridge in 2016.
The Portuguese's proximity as a direct rival at United was never likely to encourage détente.
Mourinho and Conte have met seven times before as managers.
After their first meeting was a draw in 2010 as Inter took on Atalanta, Conte has taken four victories from the six meetings to take place since 2016, with just two wins going to the new Roma boss.
Here, we have a look back at what both men said during their rivalry at Chelsea and United, reviewing how the row rapidly escalated.
Prelude - Defensive teams and Mourinho seasons
Initially, as Chelsea marched to the Premier League title and United collected the EFL Cup and Europa League to compensate for a sixth-placed finish in the top flight, the jibes between the two amounted to a sparring session, as opposed to an all-out verbal scrap.
The seeds were sown when Mourinho complained to Conte about his animated celebrations on the touchline – more on those later – as Chelsea thrashed United 4-0 at Stamford Bridge in October 2016.
Mourinho's favoured method of damning with faint praise rose to the fore in February 2017, when he labelled the Premier League's leading side "a very good defensive team", while Conte warned Chelsea to avoid "the Mourinho season" – a handy shorthand for the perils of a dreadful title defence, such as the one endured at Stamford Bridge in 2015-16.
In addition, Mourinho suggested Conte was one of his rivals who, "they cry, they cry, they cry when a player is injured". In the Italian's opinion, the United boss was overly concerned with matters at his former club. The stage was set.
'I don't behave as a clown on the touchline'
While offering assurances over his United future in January 2018, having appeared increasingly morose around matches, Mourinho identified an aspect of his behaviour he believes sets him apart from his colleagues.
"Because I don't behave as a clown on the touchline it means I lost my passion?" he said. "I prefer to behave the way I am doing it, much more mature, better for my team and myself.
"You don't have to behave like a crazy guy on the touchline to have that passion."
Mourinho could arguably have been referencing Conte, Pep Guardiola or Jurgen Klopp. All three men were asked about his comments at the time; only one took the bait.
Speaking a day later, Conte was quick to accuse Mourinho of hypocrisy in a rather eye-catching manner.
"I think that he has to see himself in the past, maybe he was speaking about himself in the past, yeah?" he said.
"Maybe sometimes, I think that someone forgets his behaviour and sometimes I think there is, I don't know the name, 'demenza senile' when you are a bit... when you forget what you do in the past."
Despite the literal translation being "senile dementia", Chelsea were forced to clarify Conte had been searching for the Italian word for "amnesia".
Either way, this was now an argument in the gutter. Mourinho seemed happy with that state of affairs and was determined to hit Conte where it hurt most.
'I will never be suspended for match-fixing'
Responding after United's 2-0 FA Cup win over Derby later that day, Mourinho set Conte up with faux-sympathy and empathy – this is all the media's fault, you see – before concluding with a non-veiled dig.
"Look, I don't blame him. Honestly, I don't blame him," he began.
"I think the press should apologise to me and to him because the question that comes to him is completely wrong and because of that he had that out-of-control reaction. But I don't blame him at all."
There followed apparent contrition for past indiscretions. It was all an elaborate set-up.
"The only thing I want to say to end the story is that yes, I made mistakes in the past on the touchline," Mourinho added.
"Yes, I will make less, but I think I will still make a few. What never happened to me and will never happen is to be suspended for match-fixing. That never happened to me and will never happen."
Conte was implicated in a 2011 scandal while in charge of Siena and later served a four-month ban, but always denied any wrongdoing and was acquitted by an Italian judge in May 2016.
'A little man with a very low profile'
Conte had spoken previously about his personal ordeal throughout the match-fixing affair. Following a 0-0 FA Cup draw for Chelsea at Norwich City, he was understandably in a barely concealed fury.
"I consider him a little man, I consider him a man with a very low profile," Conte said of Mourinho, before airing a recently learned word.
"You have to know the story very well before hurting another person. In the last period, he's suffering a bit of amnesia."
Conte went on to lambast Mourinho for his criticism of Claudio Ranieri before last season seeking to show solidarity with the deposed Leicester City boss.
"I remember for example, a stupid example with Ranieri, when he offended Ranieri for [the standard of] his English," Conte seethed.
"Then when Ranieri was sacked he put on a shirt for Ranieri. You are a fake.
"If you want to fight a person, you try to kill the person, and then after two years you try to help this person, because maybe it's good for you, your profile."
Contempt and no regrets
In the days following that year's FA Cup third-round weekend, Conte underlined that he had "no regrets" over the episode. "He said serious words and used serious words. I won't forget this," he said.
Mourinho then told reporters in no uncertain terms that he had "contempt" for Conte, as a dubious means to draw a line under the issue.
All eyes were on the dugout, then, when the foes met at Old Trafford – a prospect Conte was already eyeing as he glowered at Carrow Road.
"Me and him, face to face," he said of the Premier League match at the Theatre of Dreams. "I'm ready. I don't know if he is ready."
United came from behind to win 2-1, with Romelu Lukaku and Jesse Lingard getting the goals.
The two managers were heavily scrutinised - Mourinho was the first to emerge from the tunnel and the pair did shake hands even after a wait for Conte to make his appearance.
Mourinho and Conte again shook hands after the match and the mood seemed conciliatory.
In the months after the match and shortly before the FA Cup final between United and Chelsea in 2018, Mourinho revealed a truce had broken out between the pair.
"He [Conte] stretched out, I stretched, we got bored [arguing]," Mourinho said to Record.
"After the game here in Manchester, I invited him to come to my office. We talked, nothing is wrong."
Conte would go on to have the last laugh in their final meeting in England, beating Mourinho and United 1-0 to lift the FA Cup in his last match in charge of Chelsea before a bitter exit from Stamford Bridge.
Will the truce last? We'll find out next season and potentially for many years to come in Italy.