Lennie Lawrence celebrates a famous play-off win with Andy Campbell and Sam Hammam
The foundations were put in place for a decade-long stay in the First Division, then renamed the Championship, before the club's first promotion to the Premier League.
The club went up and up, but, sadly, Campbell's career subsequently stalled.
With promotion came cash and the Bluebirds sought to bolster their ranks and build from a position of strength. Lawrence recruited Alan Lee from Rotherham United and Richard Langley from QPR, both of whom had an impact on Campbell's playing time.
He tried to be as positive as he could and desperately tried to contribute when called upon, but from those dizzying heights of being crowned Cardiff City's promotion hero, it gradually came crumbling down once again for him.
The final nail in the coffin was when Lawrence left the club, with Dave Jones then taking the reins. It was almost like Groundhog Day back up at Middlesbrough.
"They weren't the nicest conversations," he says of his interactions with Jones.
"They were quite stern conversations. I wasn't his kind of player, he didn't want me at his football club.
"He wanted to bring in Steve Thompson and the only way that could happen was if I left. So I had a week to get that deal sorted and to get myself out of the club.
"I didn't take it great, I must be honest, I lost a lot of respect for the man.
"He had been a very successful manager before he came to Cardiff and was obviously really successful for Cardiff, which is fantastic and I'm really pleased because I have a history with Cardiff and want them to do well.
"But it ended really sourly for me, which wasn't great. I was passionate and wanted to play.
"I'm quite fiery and told him how I felt and how much I wanted to play for that football club. My family were settled there, too.
"I didn't agree with the decision but there was only going to be one winner. My days were numbered and I had to go sooner rather than later."
It's certainly a sad end to Campbell's Bluebirds story. He left in 2005 after being forced to train on his own.
"It was heartbreaking," he says.
Campbell insists that he wanted to leave a hero. He didn't want to allow it to get ugly, sitting on his money and running down his contract, playing for the reserves.
He is a proud man and it was that pride that made him want to find that enjoyment again.
He moved on to Dunfermline and admits he didn't really find his spark there, but when he dropped down the leagues it came back once again.
When you think of where Campbell was just five years before this point, it almost feels like a shame that his potential wasn't completely realised in the higher divisions.
He was schooled at Middlesbrough, learning from Fabrizio Ravanelli, Alan Boksic, Juninho, Paul Merson and Hamilton Ricard.
There is a photo of the England Under-21 side which beat Yugoslavia in a play-off to seal qualification to Euro 2020, Campbell scored the first and set up Lee Hendrie for the third and the team was teeming with top talent.
The others in the starting XI were Richard Wright, Rio Ferdinand, Frank Lampard, Steven Gerrard, Jamie Carragher, Gareth Barry, Emile Heskey, Kieron Dyer, Seth Johnson and Lee Hendrie.
England Under-21s vs Yugoslavia, March 2000: (Back row L-R) Richard Wright, Steven Gerrard, Rio Ferdinand, Gareth Barry, Emile Heskey, Andy Campbell, (Front row) Seth Johnson, Frank Lampard, Jamie Carragher, Kieron Dyer, Lee Hendrie
But fast-forward five years and Campbell's career trajectory had seen him end up at Halifax Town. He later moved on to other lower league clubs before hanging his boots up all together in 2012.
The 40-year-old went on to have two stints as manager of non-League Norton and Stockton Ancients and West Auckland Town, both up in the North East, but hasn't managed since 2015.
Does he think about going back into it?
"I got my fingers burnt a couple of times," he says. "I've had a bit of time out and it's something I want to get back into.
"I'm at an age where I'm a lot more experienced now. I thought there would be an easy progression, but there's no easy progression, you've got have an education. Sometimes you think you can run before you can walk.
"I will get back into it, ground myself again and get the same people around me who I'm happy to work with and trust.
"I want to give it a go and not have a regret that I'm not good enough."
Campbell during his time coaching Norton and Stockton Ancients
Campbell admits that he didn't try as hard as he could have in school. Once he got his YTS with Middlesbrough there was only one thing on his mind and that was becoming a professional footballer.
So, when he finished football in 2012, he went back to school to get his GCSE qualifications. Then he studied for a foundation degree in fitness instruction and sports massage before getting a sports science honours degree.
"It's something I thought I could never do," he says. "I left school with nothing, no GCSEs, so to have to start again at 32 and give it everything I've got... if I can do it, anyone can."
Campbell is now a PE teacher at Dormanstown Primary Academy in Redcar, near his home in Middlesbrough.
"There are so many different challenges, but it's so enjoyable and you get so much back," he says..
"You walk into a room and you get so many happy faces."
His job affords him the opportunity to pass on his knowledge to the aspiring sports stars of tomorrow.
He scaled the heights, played alongside the best the Premier League and England has had to offer and became an idol for one stunning, left-footed moment which rocked the Millennium Stadium.
He has seen the ugly side, too, at Middlesbrough, Cardiff and in the lower leagues, but he doesn't seem like a man who harbours any regrets about what life has thrown at him so far.
"It's all positive," he says when he thinks about his time in the Welsh capital.
"However I look back at how I left, the positives outweigh the negatives 100 per cent.
"My loan spell, the Oldham hat-trick, the following season, the promotion, the ecstasy at the Millennium Stadium, hearing the plans for the football club and moving to a new stadium. I played my part in that.
"When I saw Cardiff in the Premier League under Malky Mackay, people reminded me their club wouldn't be there if it wasn't for my goal.
"I played my part, as did others, but if it wasn't for that season, we wouldn't be where we are. Thankfully, the football club has an opportunity to succeed because of that era."
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