Shergar’s victory in the 1981 Derby at Epsom remains one of the most iconic moments in racing folklore.

His winning margin of 10 lengths is the biggest in the history of the premier Classic, which was first run in 1780.

It was a case of Shergar first, the rest nowhere – and was a dream first Derby call for Graham Goode, in his first year as commentator for ITV.

He admits owing Shergar’s jockey Walter Swinburn, who was 19 at the time, an enormous debt of gratitude for making his colossal task much simpler.

“The tag line for me was I was always very grateful to Walter Swinburn for winning so easily,” said Goode.

“It made my life on the most prestigious, most under-the-microscope race, very easy, and I was always grateful to him – which always brought a smile to his face.

“I also remember from the race John Matthias finishing second (on Glint Of Gold) saying he looked up, thought he’d won the Derby – and then he saw something many lengths ahead.

“Shergar always held a good position in the race, was always in the right place at the right time, he quickened and went on.

“He was an unbelievable horse.”

It was a staggering success that saw Shergar, who carried the famous colours of the Aga Khan, rise above the normal racehorse and become a legend on and off the track.

His racing career was guided by Sir Michael Stoute, who sent him out to win six of his eight races, taking the Sandown Classic Trial by 10 lengths and the Chester Vase by 12 on the way to Epsom, where he started a 10-11 chance and won in a stroll.

With Swinburn suspended, Shergar was ridden by Lester Piggott to win the Irish Derby by four lengths, but the young rider was back in the saddle for another four-length victory against the older generations in the King George VI And Queen Elizabeth Stakes at Ascot.

Both Shergar’s defeats came at Doncaster, where he closed his racing career with an inexplicable loss at long odds-on in the St Leger.

The wonder horse was syndicated for stud duties and arrived at the Aga Khan’s Ballymany Stud in County Kildare with everything ahead of him, but armed raiders stole him one winter’s night in 1983.

With the kidnappers apparently unaware that the Aga Khan was no longer the sole owner of the horse, demands for payment of a massive ransom came to nothing.

It all ended in tragedy, of course, and it remains a mystery as to where the horse’s remains are buried, in some unmarked grave with no plaque or statue to celebrate his glory.

Forty years on, Shergar’s name is as likely to be mentioned alongside that of another infamous absentee, Lord Lucan, as with the Derby, and feature films and TV documentaries have cast no more than a shadowy light on his final days.

The racing world, however, has not forgotten. The abiding memory will forever be of Epsom in 1981, and that wonderful moment rounding Tattenham Corner when Walter Swinburn flicked the switch and the afterburners powered on.

All that disappeared that day was the opposition as Shergar cleared away, his rivals withering to dots in the distance.