Arena: From corn field to field of dreams: David Tremayne explains how the home of the British Grand Prix flourished from its agricultural roots

WHEN Jackie Stewart's Tyrrell inconveniently selected two gears simultaneously at the very moment he was attempting to wrest the lead of the 1973 British Grand Prix at Silverstone from Ronnie Peterson, it was thrown off course and charged like an angry blue combine harvester through corn as high as its engine air intake.

In those days the venerable Northamptonshire circuit concentrated as much on its agricultural activities as it did on motor racing. Today the story is different. The tag of 'war-time bomber base' has long since faded; the corn has gone. Silverstone now rightly proclaims itself the heart of British motor racing.

In the beginning things were rather less prosaic. In 1948 the world had largely forgotten about the flat, desolate airfield. Thoughts then were more for the defunct Brooklands concrete saucer in Weybridge, Surrey, which had sustained the sport since 1907 but had succumbed to wartime factors and been sold. Then, on 2 October 1948, the RAC brought grand prix racing back with what may now seem a quaint affair but which at the time was greeted with enormous enthusiasm by a populace desperate to return to pre-war normality.

Such was the success of that opening race that further grands prix were held there. The 1950 event, in the year of the first official World Championship, was patronised by King George VI, Queen Elizabeth and Princess Margaret.

In those days the sport was still an amateur affair for most of its practitioners. The acknowledged greats - Guiseppe Farina, Juan- Manuel Fangio, Froilan Gonzales - were professionals. But by contrast Reg Parnell, that year's home-grown hero who was invited to join them in the dominant Alfa Romeo team, was a pig farmer by regular occupation.

The place had something of a garden party atmosphere, and the cars all bearing their national racing colours - red for Italy, dark green for Britain, blue for France. The drivers wore linen flying helmets and could be seen sawing away at the steering wheels in their open cockpits. Straw bales were the limit of the protection offered to racers and public alike, and sponsorship was still but a glint in the European advertising director's eye.

From Luigi Villoresi's 72mph average for that 1948 race, speeds rose dramatically over the years, until the Finnish driver Keke Rosberg threw round his Williams- Honda a hair over 160mph to win pole position for the 1986 event. And that despite a slowly deflating tyre.

In the wake of such dramatic performance increases have come a series of major changes to the circuit, which now bears little resemblance to its numerous past formats. Up until 1987 Silverstone and Brands Hatch alternated the British Grand Prix annually, but then politics gave Silverstone the monopoly. It is one of the few venues owned by the people who race on it - the powerful British Racing Drivers' Club.

Silverstone's management has always been aware of the need to stay in tune with modern racing cars and to reinvest profits. Only recently it spent pounds 1m to modify several key corners after testing accidents this season involving drivers J J Lehto and Pedro Lamy. 'Circuits have to evolve; cars change and circuits change,' says Denys Rohan, chief executive of Silverstone Circuits. 'We have retained the character of three years ago, but safety has changed beyond all recognition and we can't stand still.'

Where Barcelona and Montreal were sullied by temporary tyre chicanes, Silverstone has done the job with significantly greater imagination and empathy - and in record time. A month to the day since design work began the project was completed in time for the pre-grand prix tests, and met with universal praise from the drivers. 'No circuit is perfect,' says Martin Brundle, chairman of the newly reformed Grand Prix Drivers' Association, 'but I think Silverstone has done an excellent job.' Far from emasculating what was once the fastest Grand Prix track, the changes have actually made it better as well as safer.

Visitors to the 1948 race would not recognise the place now, but that is an inevitable price of progress. When Villoresi brought his winning Maserati to the chequered flag in 1948 the crowd politely swarmed on to the track in ecstatic celebration. Years later, when Nigel Mansell's successes stirred xenophobes in their tens of thousands, crowd invasions of a darker nature became de rigueur. One individual was even lionised after being run over in the 1992 melee. As a direct consequence, protective fences now not only keep the cars from the crowd, but the crowd from the cars.

Silverstone has become to British motorsport what Old Trafford, Wimbledon and Ascot are to their respective disciplines: a sporting venue that is the envy of the world and whose guardians - and ghosts - jealously protect a glittering heritage.

(Photograph omitted)