Former British Prime Minister Tony Blair was in Downing Street and Guardiola was winding down his playing career in Qatar the last time Arsenal were crowned Premier League champions – the 2003-04 'Invincibles' when Arsene Wenger's side went through the campaign unbeaten.
There was no perfect record this time – Arsenal would lose five games on the way to a 14th domestic title – but that did not diminish the achievement of Mikel Arteta and his players after three successive runner-up finishes.
Or the celebrations that followed as thousands danced and sang outside the Emirates Stadium, where Ian Wright sprayed champagne, and at impromptu street parties that lasted until 5am on a mild Wednesday morning.
Goalkeeper David Raya won the Golden Glove for the third season in a row with 19 clean sheets as Gabriel and William Saliba formed a formidable barrier in front of him.
Declan Rice was immense in midfield and Viktor Gyokeres shrugged off concerns over his finishing to score 14 goals after his arrival from Sporting Lisbon.
Despite criticism that Arsenal were not expansive enough and relied more on functionality than artistry, Arteta's side have also made their way to a Champions League final against holders Paris Saint-Germain.
Arch rivals Tottenham, meanwhile. Europa League winners 12 months previously, were involved in a relegation battle that went to the final day.
Thomas Frank and Igor Tudor both arrived and departed before Roberto De Zerbi secured Spurs' safety.
Burnley, West Ham United and Wolverhampton Wanderers dropped into the Championship and played their part in the managerial merry-go-round.
Scott Parker left the Clarets, Nuno Espirito Santo replaced Graham Potter at the Hammers and Rob Edwards succeeded Vitor Pereira at Wolves.
Pereira resurfaced to lead Nottingham Forest to a Europa League semi-final and Premier League survival after owner Evangelos Marinakis had pulled the trigger on Nuno, former Socceroos and Spurs boss Ange Postecoglou, and Sean Dyche in a chaotic campaign.
In Manchester, it was a case of hello and goodbye in the blue and red halves of the city.
Guardiola said his farewells at City after 10 years and 20 trophies – missing out on a seventh Premier League title as a slow start cost them dear.
Energised by the January additions of Antoine Semenyo and Marc Guehi, City's only loss after a derby defeat to United on January 17 came on the final day at home to Aston Villa. Erling Haaland won the Golden Boot again with 27 goals.
Michael Carrick replaced Ruben Amorim in January and turned around United's fortunes, with the help of Bruno Fernandes' Premier League-record 21 assists.
Having finished 15th last season when Amorim declared "we are the worst team maybe in the history of Manchester United", the Red Devils finished third and returned to the Champions League after a three-year absence.
Fourth-placed Villa also secured Champions League football and ended a 30-year wait for silverware by winning the Europa League.
Champions Liverpool fell to fifth after a campaign that began with the tragic death of forward Diogo Jota in a pre-season car accident.
Big-money signings Alexander Isak and Florian Wirtz failed to justify their price tags while Mohamed Salah accused Arne Slot of throwing him "under the bus" following a 3-3 draw at Leeds United in December and made an another apparent attack on the manager in the closing weeks after Salah's Anfield departure had been announced in March.
Bournemouth and new boys Sunderland qualified for the Europa League with the Black Cats finishing five places above bitter rivals Newcastle United, who were 12th.
Brighton & Hove Albion made the Conference League as Brentford, fuelled by 22 goals from Igor Thiago, just missed out on Europe in Keith Andrews' first season in charge.
Chelsea slumped from fourth to 10th and sacked Enzo Maresca and Liam Rosenior along the way. The appointment of Xabi Alonso offers fresh hope for next season.
Fulham – who must fret over the futures of manager Marco Silva and top scorer Harry Wilson – just missed out on European football, while Everton fell away at the end of their first season at the Hill Dickinson Stadium.
Leeds consolidated after sticking with Daniel Farke following promotion.
Crystal Palace were 15th but could conclude the season with UEFA Conference League glory on Wednesday (Thursday AEST) in Oliver Glasner's final match in charge.
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