Above it all, Leeds United v Manchester United is a footballing rivalry. Scratch the surface a little, though, and it is also an inter-city dispute between urban sprawls 39 miles apart. Dig further, and county roots begin to show. It's Yorkshire versus Lancashire, the War of the Roses. A prickly affair.

The white rose of Yorkshire against the red of Lancashire. Both sets of inhabitants like to refer to "God's Own Country" when speaking of their territory. At Old Trafford, that is one reason why they boo the name England and chant Argentina's instead. Manchester and Lancashire, they think, are superior to England.

Such subversiveness would never be tolerated at Elland Road. Yorkshire-men consider themselves the keepers of England's soul and as such don't like giving anything away. Especially for nowt. Which is one reason why the departure of Eric Cantona hurt so much. At £1 million, they always felt he was a give-away. You should not give anything away in Yorkshire, particularly if the recipient is Manchester United. That was in November 1992.

It will be of some annoyance to Yorkshire-men therefore to discover that at the same time Cantona was leaving the county a man called Jaap Stam was entering it for a trial. It was at Hillsborough, co-incidentally where Cantona had started his English odyssey.

Stam, a quiet young man, came and went without disturbing the natives too much. He was 19. When he returned to England to sign for Man United, he was 26. He was £10.75 million as well. He was the planet's most expensive defender. He was about to win the Treble. One man, two eras, separated by a financial light year.

Where Jaap Stam is concerned, however, trying to prise out some colour on the contrast of the two is about as easy as beating him in the tackle. A crowbar would be helpful. Then again, as Gary Neville said of his colleague: "He's not really boisterous. He's a calm man."

In conversation Stam is so calm he could be asleep. Maybe that is just with reporters. In our company Stam's reticence is palpable, almost painful. Clearly he hates this aspect of his job. Perhaps it is no surprise that he should have a great defence mechanism - silence.

Lately, though, a change appears to have come across Jaap Stam. At least, on the pitch he seems to have found his voice. In the newspaper in which he contributes a ghosted column, in recognition of his recent verbal gymnastics, they have christened him Yap Stam.

Last Saturday at Newcastle he was booked for dissent in the second half after his far-from-placid berating of a linesman. It was a remarkable Stam outburst, especially as in the morning he had written about the outcry following United's players' harassment of referee Andy D'Urso during the Middlesbrough game a fortnight earlier.

Then Stam had been in the middle of things again, his tackle on Juninho being worthy of a penalty in Mr D'Urso's eyes. Stam's reaction, along with Roy Keane's, was unlimited fury. D'Urso looked like a hunted animal. The menace in Stam's demeanour must have been frightening. He is 6 ft 3 in, 14 st and has his head shaved once a week by his wife, Ellis.

"The photographs in the newspapers the next day didn't look pretty," Stam said. "Many people who weren't there are basing their judgments on that. But we didn't touch the referee or call him names, we were just very angry at the decision."

Stam went on to say, correctly, that Manchester United have the lowest yellow card count in the Premiership - less than half that of Leeds - and refuted the allegation that the club deliberately bullies referees.

"That's rubbish," he said, "anyone who watches me play regularly will tell you that I hardly talk to referees at all. But sometimes when a decision seems so unfair you just react spontaneously."

Spontaneity is not the most conspicuous characteristic one would attribute to Stam. His hobby is fishing. At home, he has a goldfish and cats. He met his wife when he was 16 and she was 15. "Reliable" is the description Alex Ferguson uses.

Stam is a bit more than that: he is spectacularly reliable. Frequently swamped in the avalanche of publicity surrounding United's Treble achievement last May was the fact that the catalyst had been a trophy-free season the year before. It was that which persuaded Ferguson to persuade Martin Edwards to part with £23.35 million for Stam and Dwight Yorke. By the triumph in the Nou Camp both had justified the outlay in the space of a year.

In Stam's case, though, his uncertain beginning had not suggested such a glorious end. Described as "Steve Bould on ice" during the World Cup, Stam's first United game was in the Charity Shield at Wembley. Arsenal won 3-0.

In his first league game at Old Trafford a week later Stam was replaced by Henning Berg, and it was not until November that Stam was convincing a doubting public.

Then, after a 3-1 defeat at Sheffield Wednesday - Stam back at Hillsborough - Ferguson said "only Jaap Stam performed like a Manchester United player".

It is a mark of Stam's impact and United's amazing success that after the Wednesday game they lost only one match in three competitions - the Premiership, the FA Cup and the European Cup, including the Champions' League group phase.

In a season of 10 months Stam won five Player of the Month awards at United.

Ferguson's vindication was also Stam's. At PSV Eindhoven, Stam had a clause in his contract which entitled him to 15 per cent of any sell-on fee. When Ferguson came calling with his big chequebook that meant more than £1.5 million was Stam's. He forfeited half to ease the transfer. With these kind of sums that may not amount to more than a gesture, but at least he made it.

The impression is of a man who appreciates his privileges. The son of a carpenter in rural Holland, Stam was still persevering with an electrician's course right up until he made the move to FC Zwolle. He was 20. From there it was on to Willem II of Tilburg, and then PSV, where he played under Dick Advocaat - "He taught me patience".

International recognition came at PSV, and in his last season there he was voted Dutch Players' Player of the Year. Though his last match was a 5-0 defeat by Ajax, a World Cup semi-final against Brazil followed, when he marked his old PSV team-mate Ronaldo, and then United and a hat-trick of medals.

As with adversity, success breeds friendships. "I have great affection for my team-mates," Stam said, "from the start they made me one of them. They didn't leave me in a corner to fight my way in. The biggest surprise was how relaxed the manager was. Arriving at the world's biggest club led me to expect a certain strictness and rigidity. Alex Ferguson isn't like that."

The man whose name's literal translation from the Dutch is Jack Tree Trunk has shown similar versatility. In Yorkshire, they must wish he had put his roots down there.