Pep Guardiola once described Jose Mourinho as the "puto amo" ("f*****g boss") of the press room during one of their heated exchanges in Spain. Today, two weeks after Mourinho was presented as Chelsea's new coach, Kaiser Pep will be unveiled as the new man at Bayern Munich and is preparing to bring the house down by speaking in fluent German.
"He has been studying like a madman" says his brother, the football agent Pere Guardiola, while other former players have said they are not surprised the ultra-professional former Barça manager comes into the job perfectly prepared.
Mourinho and Guardiola will come face to face again in the European Super Cup in Prague on 30 August. The theme of Pep against Mou is likely to continue this season as Chelsea emerge as one of Bayern's main rivals in Europe. For all last season's glories, Bayern still look back with anger at that missed opportunity to win the Champions League in their own stadium last year, which was spoiled by Chelsea.
Guardiola may also find enemies within Bayern if he does not get off to the best of starts or if he disagrees with the hierarchy over who is sold and bought. One of the secrets of his success in his four years at Barcelona was the power that he had to get rid of big-name players. Upon taking charge at the Nou Camp he demanded Deco and Ronaldinho be sold. Next summer Samuel Eto'o left and youth team golden boy Bojan Krkic and Zlatan Ibrahimovic were others.
In his final year there were even suggestions Guardiola had asked for Gerard Pique to be moved on before deciding he would go instead. What will happen at Bayern if he decides to sacrifice sacred cows?
He has to answer to the president, Uli Hoeness, director -general Karl-Heinz Rummenigge and sporting director Matthias Sammer, although they all chose to bring in Guardiola so it is in their interests that he succeeds.
The new man has brought coaches Domènec Torrent and Carles Planchart from Barcelona. He hired both in 2007 when he was coach of Barcelona B and they helped the reserve team win promotion to the second division, staying with Guardiola when he became first-team coach in 2008. Planchart will supervise analysis of opposing teams and Torrent will be Guardiola's assistant alongside Hermann Gerland, who has been at Bayern since 2001. He is the former B-team coach and will be an asset as Guardiola looks to sustain Bayern's ability to draw on their youth academy. Six of last season's 24-man squad were homegrown.
Guardiola's most important ally will be Lorenzo Buenaventura, who he brought to Barça in 2008 as fitness coach and who transformed them from Frank Rijkaard's talented but one-paced side, to Europe's most intensive team. Guardiola wanted a team that would chase possession within seconds of losing it, but Buenaventura conditioned the players to do that.
Guardiola will also have life-long friend Manuel Estiarte, the former Olympic water-polo gold medal winner, with him. Estiarte has been an ally abroad for Guardiola and supported him when he was banned for alleged doping in Italy in 2001 – he was absolved of any wrongdoing in 2007.
Win at Bayern and the coach who has a €17m-a-year salary (£14.5m) will extend the "little Barcelona" entourage he has established in Bavaria; falter and his "clique" will be seen as burden on the wage bill. Bayern's honorary president Franz Beckenbauer said after Jupp Heynckes' treble that things "couldn't get any better". It is down to Kaiser Pep to prove him wrong.