It was six years ago that Ricardo Carvalho ended a glittering playing career that brought pretty much every piece of silverware going, but he is still a busy man thanks to his new job on the coaching staff of the Portuguese national team.

He is never too busy to discuss his time at Chelsea, though. Fresh off the training pitch in his homeland, where he was helping prepare Portugal for their final match of Euro 2024 qualifying, Carvalho was only too happy to cast his mind back 20 years to share his memories of life with the Blues.

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In recent months we have been catching up with several players who were part of a foreign enclave at Chelsea. Each made a huge and lasting impact at the club, but perhaps few were as noticeable – or to as much public fanfare – as the Portuguese exodus to Stamford Bridge in 2004.

It was the start of a new era for Chelsea. While we had made a stir with some great transfer coups in the past, especially with the initial arrival of foreign stars in the 90s, nothing like this had ever been seen before. Not in England and certainly not at Chelsea.

For perhaps the first time, the Blues were signing the most sought-after players in world football, and beating competition for their signatures from the historic big clubs of Europe.

Perhaps it was only natural that several people would swap one perceived upstart – fresh from upsetting the natural order of things – for another.

At the end of the 2003/04 season, Porto stunned everyone by lifting the Champions League trophy, becoming the first Portuguese side to do so since their own previous triumph in 1987.

With Chelsea looking to end a 50-year wait for a top-flight league title, it seemed the natural place to search for new faces and fresh ideas.

That summer, Jose Mourinho arrived as manager, and he brought his coaching staff, star defenders Carvalho and Paulo Ferreira, and a few others who had caught his eye in Portugal.

The rest, of course, is history, as success arrived instantly in the form of a Premier League and League Cup double, before defending the title in 2006, and adding the FA Cup a year later.

‘It was almost at the same time in 2004,’ recalls Carvalho. ‘It was Mourinho who signed the contract first and I think at that point it was already in my head to join. The first player to sign was Paulo and then Tiago Mendes from Benfica, and at the end was myself in August.

‘So when I arrived, there was already the technical staff I worked with in Porto, my team-mate Paulo, and Tiago, who I’d built a great relationship with.

'Of course, adapting was a little bit easier because I knew the methods that Mourinho was training and also the language. But in the end, the important thing was that we had great players in the club.’

It is there that Ricardo begins to explain how the close bond within that hugely successful Chelsea squad transcended nationalities, despite the fact the Portuguese presence in the squad continued to grow throughout his time in England.

The bond was one born out of an underlying professionalism and a hunger to win, which grew ever stronger with each new moment of success. And there were plenty.

‘You are there to play,' he says. 'Of course, it’s good to see people that speak Portuguese and you have a good relationship with, but after I still have a good relationship with the other guys I met there, like Didier Drogba.

'We don’t speak often but when we do it’s about remembering those times and how we miss each other. It was a very good team spirit.

‘That's because we started to win. For a team to grow it’s important to win, and we started to win games from the beginning. That helped a lot.

‘I spent six years at Chelsea and in the first three years we had Paulo, Tiago, then after that came Hilario, then Bosingwa, who I also have a very good relationship with, and others too.

'So it was good to speak in the dressing room; after we’ve got our families and your own lives. But everyone was so social at that time at Chelsea, the results helped a lot for us to feel that we were a team.’

It is fair to say, helped by that success on the pitch, Carvalho rapidly overcame any initial teething problems at Chelsea, and that was reflected in life away from football.

In fact, he admits the biggest problem he faced in adapting to life in England came not when he first arrived in the country, but during a change of location within it, as he decided to swap the hustle and bustle of London for the countryside surroundings near our Cobham training ground.

‘In the beginning, the first year, it was more difficult because the language was a barrier, but after I enjoyed living in England a lot, the life was nice.

'Also, at that time, I thought because I was in London I had to enjoy it a little bit. Not to go out all the time or anything, but just to walk and have coffee and spend a little bit of time with my wife was nice.

‘In my first two years, I was living close to Stamford Bridge. But later when the kids started to grow up, I tried to go to Surrey, near Cobham.

'Lamps [Frank Lampard] knew me well and we would cross paths on King’s Road and go for a coffee. So Lamps told me not to go to Cobham because I liked to live in the city. He was right! I tried to go to Cobham but I didn’t adapt. I went straight back to the city!

‘I enjoyed it a lot, being around the Chelsea area, and it was nice for my family. The time when I went to Cobham was nice – I had a big house with a garden and everything that you can’t really have in the city – but I didn’t have people and places around me.

'I was used to having a coffee on the street with my wife, taking in London, that kind of life. So I enjoyed it more in the city.

‘For us, as players, it is always most important to play well and to have success with the club, though. After that, life was good, even though at the beginning I was just focused on playing well, adapting as quickly as possible to the pace of English football, with more long balls, headers, everything. The strikers were bigger and stronger, but the life was nice!’

Having the likes of Ferreira, who went through the same transition, no doubt helped Carvalho in adapting to the Premier League. There was a strong English core to the team to point the way, too, with the likes of Lampard, Joe Cole, and John Terry regular starters.

It was the latter who proved especially important. Having come through the Chelsea Academy to captain the side, there were few who knew English football or the club as well as Terry.

And it telling that not only did Carvalho succeed here, he formed one of the best centre-back pairings the Premier League has ever seen alongside Terry.

‘For me, as a defender, he was an example, because he grew up in England and I grew up in Portugal, with different ways of playing. Here the pace, the long balls, and everything, it was different, so I had to improve my game in those areas.

‘I was talking to him from the beginning and after we enjoyed ourselves; we had a very good relationship together and we started to know each other quickly. Sometimes we didn’t even need to speak, it was just about looking at each other and I knew what he was going to do.

‘He knew that I liked to cover, I knew that he liked to fight for the first balls, so it was automatic. Those are the kind of things you feel and it is difficult to explain in words.’

Of course, it is difficult to speak about Chelsea in that period, and especially the Portuguese influence, without discussing Mourinho in more detail.

It seems strange now to think that when the coach arrived at the Bridge he was still relatively unknown in England, despite his achievements with Porto.

Almost 20 years on, the success Mourinho enjoyed at Chelsea is well-known, as is how he and his teams thrived under pressure, to the extent Mourinho would seemingly create it to keep his charges on their toes.

He was a manager who operated on the edge emotionally, a harsh taskmaster who gave everything in pursuit of victory and expected the same commitment from his players.

That intensity must have been a shock for the majority of the squad, especially those unaware his constant haranguing was designed to ensure the team met those high standards, rather than a personal vendetta.

However, when it is put to Carvalho that his previous knowledge of Mourinho’s methods must have made things easier, the suggestion is greeted with laughter.

It seems to have been quite the opposite, with Jose often offering up those who knew him best as sacrificial lambs, demonstrating to the rest that anyone could become the unfortunate focus of his formidable anger if he felt it would improve performance.

‘Maybe at the start with the technical staff, it helped to have me and Paulo there. Jose knew us very well, he knew how we reacted with bad words or good words.

'Myself and Paulo respected the way he is and in Portugal, it was always that the coaches were for speaking and the players were for training. So we didn’t complain a lot!

‘He liked working that way at that time. But, to be fair, the wins helped and everyone in the club respected the way Mourinho was at that time, so we didn’t take the bad words personally.

‘That was just the way he was – and the other players knew because Jose was the same when he shouted at me or shouted at Paulo or Tiago. The others saw that you didn’t react, you just respect. He’s the boss, that’s him, so you just have to try to do your best.

'Maybe it was a good way for Mourinho to show to everyone that he was the boss. If he shouts at me, he shouts at Paulo, then he can shout at everyone. It’s the way he is.

‘To be fair, even JT, Lamps, Drogba, everyone, he earned their respect because you want to win. Sometimes it happens that you don’t agree with what the coach says, or you have a different way of thinking, but in reality when you go to the games and you win, after that you start to believe that maybe you are wrong and his way works.

'So we had to follow him because he was getting victory after victory and as players, we were getting stronger.

‘In the end, we won the Premier League after 50 years of Chelsea not winning it, so it’s more about that. Even if we don’t agree with something, if you have your own ideas, when you see that he’s getting victory after victory you have to believe in him and you have to follow him.’

That advance knowledge of the price of success under Mourinho perhaps helps make it less of a surprise that, despite what would seem obvious, it was not the chance to join so many familiar faces from Portugal at Chelsea which was the crucial factor in his decision to come to SW6. It turns out that was just a bonus.

In 2004 Carvalho was very much in demand, fresh from his starring role in Porto’s Champions League victory and Portugal's run to the European Championship final.

It is fair to say he had options, but he was never the kind of person who would take the easy one.

It was U.S President John F. Kennedy in the 1960s who, announcing his plan to send man to the moon, famously declared: ‘We do these things not because they are easy, but because they are hard’.

It is a philosophy Carvalho seems to share, with the most difficult challenge available to him holding the most appeal.

‘After I won the Champions League at Porto, my goal was to play in the Premier League. Of course, it was good to be with Mourinho because I knew his way of working and his methods, and being with the technical staff that I knew and won a lot of things with was great, but I would have taken the same move anyway.

'I like to prove myself and the next step for me was to play in a better league. That was the part that made the decision easy.

‘During my career, I always wanted to put pressure on myself. To arrive in a physical game like the Premier League did that. Because I grew up in Portugal, it would have been easier for me, with my characteristics, to go to Spain. The way football is in Spain would have been easier for me to play in.

‘It was a big step but I always wanted to put the pressure on myself, show that I can deal with big guys, big strikers. A lot of centre-backs at that time were also strong; I wanted to prove that I could fight with them and improve.

‘Porto didn’t want to let me go but I knew that I could be a success in England.'

He wasn’t mistaken and, over six years, Carvalho proved himself to be one of the best centre-backs to represent Chelsea and silenced any doubts about whether he could repeat his Porto performances in the fiercely competitive surroundings of the Premier League.

Just like Mourinho, Ricardo’s success speaks for itself.