On Saturday, Jose Mourinho and Rafa Benitez reignite an old rivalry for the first time since August 2007 as Newcastle United visits Manchester United at Old Trafford. These old touchline foes may claim to be focusing only on the match at hand, but have a bit of personal history to consider all the same.
Here are the three major storylines in the Mourinho-Benitez feud:
Nursing Champions League woes
In 2005, Chelsea was eliminated by Liverpool in the Champions League due to a "ghost goal" scored by Luis Garcia but cleared off the line by William Gallas. Whether legitimate or not, it was enough for Benitez's side to beat Mourinho's, and advance to the final, where they came from behind to defeat AC Milan.
Predictably, Mourinho was none too pleased with the referee's decision.
"You can say the linesman's scored," Mourinho waxed. "It was a goal coming from the moon or from the Anfield Road stands."
It sparked dislike between the two, and while Mourinho was certainly the more vocal party, it was Benitez who got the better of his opposite, whether in the following Champions League or the FA Cup. Mourinho won Premier League titles with Chelsea, but Benitez was still critical of his Portuguese adversary.
"To me, Arsenal play much better football. They win matches and are exciting to watch. Barcelona and Milan too. They create excitement so how can you say Chelsea are the best in the world?" Bentitez said.
My trophy case is bigger than yours
Mourinho seemed bothered by Benitez's appointment as his replacement at Inter Milan - Benitez also stepped in for Mourinho, indirectly, at Real Madrid and Chelsea. When Benitez took over at Inter, Mourinho made a bold prediction: "One thing is for certain. Benitez won't do better than me. Another thing is also true that should he lift the Intercontinental Cup, he will have only won two games compared to my 13. Therefore it will be my trophy and not his."
When Inter went on to win the Club World Cup, Mourinho quickly weighed in: "I expected at least a thank you for the success that I gave him. Ask all the Inter fans what they think of me and him."
And, when Benitez guided Chelsea to a Europa League title, Mourinho couldn't resist: "I don't want to win the Europa League. It would be a big disappointment for me. I don't want my players to feel the Europa League is our competition."
Mourinho went on to celebrate a Europa League title with United last season.
For his part, Benitez stayed mostly quiet during this time, before offering:
"Mourinho talks a lot about a lot of people, but I prefer to talk about facts. At Liverpool, with a squad half of the value of Chelsea, we twice knocked his Chelsea side out of the Champions League. Later, with the most expensive squad at Real Madrid, he did nothing in the Champions League."
Tidying up after Mourinho
In 2015, Benitez's wife joked: "We tidy up (Mourinho's) messes. If you think about it, of course you end up crossing paths. There are only a few world-class clubs out there."
Mourinho quickly retorted: "The lady is a bit confused, with all respect. I'm not laughing, because her husband went to Chelsea to replace Roberto Di Matteo and he went to Real Madrid and replaced Carlo Ancelotti.
"The only club where her husband replaced me was at Inter Milan, where in six months he destroyed the best team in Europe at the time.
"And for her also to think about me and to speak about me, I think she needs to occupy her time, and if she takes care of her husband's diet she will have less time to speak about me."
(Photos courtesy: Getty Images)