It was a memorable time for both Chelsea and Jose Mourinho. The self-styled 'Special One' more than lived up to his moniker with back-to-back Premier League title wins in 2005 and 2006.
Mourinho's first spell in charge at Stamford Bridge lasted three-and-a-bit years and there were plenty of players who came and went, with Russian owner Roman Abramovich determined to make his mark on English football.
Two such players from that era have been in the news recently after they landed new jobs in management. Damien Duff is going to manage Irish club Shelbourne and Andriy Shevchenko has taken over at Serie A side Genoa.
Quite a few of those who played under Mourinho at Chelsea have been inspired to enter management or coaching with a handful going full circle and coming back to the club.
A few others are pundits on television while some have taken career paths less expected of a retired football.
Here's a look at what has become of a few of the Chelsea players from Mourinho's first spell at the club.
Damien Duff
The former Chelsea, Blackburn and Newcastle winger last week landed his first job in management at Irish top-flight side Shelbourne. After retirement in 2015, Duff has taken on various coaching roles at Shamrock Rovers and with the Republic of Ireland youth teams. He was a first-team coach under Neil Lennon at Celtic and has been assistant to Stephen Kenny for Ireland.
Andriy Shevchenko
Things didn't work out too well for Shevchenko under Mourinho after he was signed in 2006 more at the behest of owner Roman Abramovich. But the Ukrainian is also now in the management game and was recently appointed boss of Serie A club Genoa. He previously spent five years in charge of the Ukraine national team, leading them to the quarter-finals of Euro 2020, where they lost 4-0 to England.
John Terry
Chelsea's Captain Marvel also went down the coaching route after retiring from the game in 2018. Having finished his career at Aston Villa, he was appointed assistant to Dean Smith and spent three years with the club. Having left in July, Terry is now looking for a first management role, though it's his arrival on Twitter that's currently causing more of a stir.
Frank Lampard
Another Chelsea player from that era who could soon be back in the dug-out. Having been sacked by Chelsea back in January as his second season in charge quickly unravelled, Lampard then held talks for the Norwich City job but pulled out of the running, allowing Dean Smith to take the role. Prior to leading his old club to a fourth place finish and the FA Cup final in 2019-20, Lampard almost guided Derby back into the Premier League, losing a play-off final.
Joe Cole
We've become accustomed to hearing Cole's opinion on BT Sport's coverage of the Premier League and the Champions League these past few years. But he too has his coaching qualifications, having worked in a player/assistant manager role for Tampa Bay Rowdies at the end of his career and then in Chelsea's academy. He left that latter role in 2020 but all options remain open to him.
Petr Cech
The former keeper is Chelsea's technical and performance advisor, having returned to Stamford Bridge in 2019 after seeing out his playing career at Arsenal. He came out of the stadium to try and placate angry fans protesting against the European Super League earlier this year before the club u-turned on its decision to join. Cech still plays as an ice hockey goaltender for Guildford Phoenix of the National Ice Hockey League Division Two.
Glen Johnson
As well as occasional punditry work on radio and television, the former England right-back has devoted time in retirement to his property development business and an investment company called Bed of Honey, which has stakes in real estate, art and fine wine.
Claude Makelele
Another still involved at Chelsea as a technical mentor and youth coach in the club's academy. Makelele went into coaching pretty much straight away after retiring at PSG in 2011. He was assistant there to Carlo Ancelotti and subsequently went on to manage Bastia and Belgian club Eupen before returning to Chelsea.
Alexey Smertin
Not exactly a regular under Mourinho but a 2005 Premier League champion nonetheless. Smertin works for the Russian Football Union as director of regional policies and internationals relations, as well as fulfilling an anti-racism role started before the 2018 World Cup was staged in the country.
Ricardo Carvalho
The Portuguese defensive rock served as assistant manager to Andre Villas-Boas at Ligue 1 side Marseille until the pair left the club back in February. He only stopped playing in 2017, at the age of 39, with Chinese club Shanghai SiPG his final stop.
Mateja Kezman
Chelsea fans were taken aback when pictures of Kezman emerged on social media last year - the Serbian former striker had a wild grey beard and looked much older than his 42 years. After serving as a director of Serbian club FK Vojvodina shortly after retirement in 2012, he became a football agent with Lazio star Sergej Milinkovic-Savic one of his clients.
Geremi
The Cameroon international could either play at right-back or in midfield and racked up over a century of appearances for Chelsea. He now works for the Cameroon Football Federation and recently ran unsuccessfully for the presidency of the organisation alongside Samuel Eto'o. Geremi is also trying to improve the lot of Cameroonian footballers through his role as president of their national players' union.
Didier Drogba
The most prolific goalscorer of Mourinho's first spell at Chelsea only hung up his boots in 2018 at the age of 40 after winding down his career in the United States. Drogba is the vice president of the Peace and Sport organisation as well as running his own charitable foundation. He also continues to haunt Arsene Wenger - he scored a hat-trick recently for a Marseille legends side against Wenger's UNICEF XI in a charity game.
Arjen Robben
The Dutch winger went on to play for Real Madrid and Bayern Munich after leaving Chelsea in 2007 and has only just retired from playing, aged 37, after finishing his career at Groningen.
Scott Parker
Another who has successfully made the step into management, helping Fulham into then Premier League in 2020 only to suffer relegation back to the Championship after just one season. Parker left and is now manager of Bournemouth, currently top of the Championship.
Eidur Gudjohnsen
The Icelandic striker is now assistant coach of Iceland's national team under Arnar Vidarsson. They previously worked together for the Iceland under-21 side.
Jiri Jarosík
The Czech joined half-way through Mourinho's first season in charge at Chelsea. He is now the manager of Teplice in his home country.
Michael Essien
A formidable presence at the heart of Chelsea's midfield for many years, making over 250 appearances for the club. The Ghanaian is now a member of the coaching team at the Danish club Nordsjaelland. The club has linked with the Right to Dream Academy based in Ghana.
Michael Ballack
One of the signings during the later part of Mourinho's first spell at Chelsea, the ex-Germany captain has been a prominent pundit both in his homeland and in England since retiring from playing.