One was the British royal standard, flown from the roof of the County Stand to greet the arrival of Queen Elizabeth, Princess Margaret and the Queen Mother. The other, fixed to a flagpole opposite the stand, was the hammer and sickle, flapping in the easterly wind in honour of Georgi Malenkov, the recent Soviet premier who was visiting Britain and taking in the great race.

A race that invariably throws up the dramatic and occasionally throws up the bizarre. A race that on 24 March, 1956 threw up the grotesque, the unbelievable, the unprecedented and the unrepeatable besides.

There have been memorable Grand Nationals since then. Foinavon at 100/1 amid 1967's chaos. Red Rum and Crisp in 1973. Red Rum's third in 1977. Aldaniti and Bob Champion, the crock and the cancer victim, in 1981. But there's never been a renewal like the 1956 National, nor will there be again. Had it been any other owner and any other jockey, the race would still have been remembered. Because it was this particular owner and this particular jockey, the 1956 Grand National . . . Devon Loch's Grand National . . .

became immortalised.

What would Malenkov and the other 250,000 spectators have seen on coming in the gates? A crumbling racecourse. Fearsomely high fences with sheer, cliff-face drops. Three horses had been killed over the National course on the Thursday, leading the Liverpool city branch of the RSPCA to write to the Aintree stewards and the British SPCA to write to the Home Secretary.

Though there hadn't been a royal winner of the race since Ambush in 1900, the Queen Mother's Devon Loch, ridden by the Welsh-born Dick Francis, an RAF pilot during World War Two, ticked many of the right boxes. A slow starter in races over park courses, he was likely to be better suited to Aintree; his clean jumping was an obvious plus; and 17 days beforehand he'd run a fine Grand National trial when coming home like a train to finish third in the National Hunt Handicap Steeplechase at Cheltenham.

Twelve months earlier, Quare Times had run well in the same race prior to completing Vincent O'Brien's Grand National treble: another pointer.

With two past winners and one future winner in the field, the 1956 National was not an easy race to call. But the previewer in The Times got it right . . . morally right, at any rate. There was, he asserted, little to choose between the Fred Rimell-trained ESB, a durable 10-year-old who'd been steeplechasing since he was four, and Sundew. But Devon Loch's chance "seems second to none". One of the reasons the previewer shied away from ESB was the belief that the horse would be wearing blinkers and thus wouldn't have a wide field of vision, so necessary in a race with animals falling or running loose on all sides. This day, however, ESB . . . ridden by Dave Dick and named not after a certain Irish semistate company but after the initials of his parents, English Summer and Bider . . . didn't wear blinkers.

The 29-runner field, which included the 1954 winner Royal Tan with Toss Taaffe ("a grand horse to ride but an oul' rogue, " Taaffe recalls with affection), set off at the usual cavalry-charge clip. The first fence yielded four casualties, among them Must, the 7/1 favourite, and Early Mist, O'Brien's 1953 victor. Armorial III, the tallest horse in the field, cut out the running with Sundew. Devon Loch stayed wide under Dick Francis, out of trouble but never out of touch.

Heading out into the country on the second circuit, the combination of the fast pace and drying ground began to take their toll. Sundew fell at Becher's and Armorial III at the fence after Valentine's, at which point the Queen Mother's light blue and buff stripes and gold-tasselled black cap hit the front. At the second last Devon Loch led from Eagle Lodge, ESB and Ontray. He gained in the air at the last and, full of running, began to pull clear of the toiling ESB, who was carrying a pound less. "Go on then, you lucky devil, " Dave Dick called to Francis.

What happened next has been told a thousand times and has never varied in the telling. Fifty yards or so from the winning post, well clear of ESB, with (the words of The Guardian) "hats, racecards, emotions all in the air", Devon Loch collapsed. Pancaked.

Bellyflopped. Did a Bambi on grass. Forelegs splayed out in front of him, hindlegs back behind him.

He didn't actually fall over.

Francis didn't actually fall off. The jockey urged his mount back upright as the green and white colours of ESB flashed by them on the outside, but Devon Loch's legs were wobbling grotesquely.

Francis dismounted, threw down his whip and burst into tears on hearing the sympathetic applause.

Far from being an orphan, this mishap had a thousand fathers. Did Devon Loch have a minor heart attack? Was he spooked by the shadow of the water jump on his left?

Was it what a nearby police officer identified as a dark wet patch on the course that had caused him to stumble?

Or had he been literally floored by the crescendo of jubilation from a quarter of a million people born and bred to revere their royal family, a sonic boom that at this remove can only be guessed at?

Francis has always favoured the latter theory. "I still think it was the crowd yelling, " he declared in a 1992 interview.

"As Devon Loch approached the outside of the water jump, he pricked his ears as if to say, 'I was here last time round.' As he did that, his hind quarters just refused to act. He brought his forefeet up to stop himself going over. We slid along the ground, his forefeet out and his hindfeet behind. How I didn't fall off him, I don't know. He got to his feet and if I could have got him going we were still far enough in front to have beaten ESB, but as he got up he more or less collapsed again. His legs gave way at the back, so I had no option but to get off him." An ambulance drew up alongside as the heartbroken Francis trudged away and the jockey gratefully obeyed the driver's invitation to jump in the back.

But for the freakishness of fate, Devon Loch would not only have won the Grand National with ease but would have smashed Golden Miller's course record to pieces; as it was, ESB came within a fifth of a second of it.

Gentle Moya ran on to be second with the gallant Royal Tan finishing in his own time under his welter burden of 12 stone 1 to fill third place. "He didn't travel going away from the stands, but once he turned the canal coming home he ran on, " says Taaffe, who had no idea of Devon Loch's outrageous misfortune until afterwards.

Watching from Lord Sefton's box, the royal party were suitably horrified.

Asked by the Queen Mother what had happened, Francis could only muster a simple "I don't know". "Well, that's racing, " she responded philosophically. She later presented him with a cigarette box, a memento of the Grand National the pair of them had all but won. Dave Dick was also summoned to meet the unlucky owner, a meeting which gave rise to the following exchange.

"What did you think when my horse fell down?"

"I was absolutely delighted, ma'am!"

It's fair to say there would not be a luckier Grand National winner until Foinavon 11 years later. It's also fair to record Dave Dick's assertion that ESB had been brought to a standstill by a riderless horse at the fence after the Canal Turn. But for that, according to Dick, he might have won the race by rights, in which case Devon Loch would have quickly been forgotten and Francis might never have become an author.

Neither eventuality occurred. The Devon Loch affair has entered the sporting lexicon in these islands.

(When Alex Ferguson wrote to Kenny Dalglish to congratulate him following Blackburn Rovers's 1995 Premiership title success, he admitted he'd hoped Dalglish's team might have "done a Devon Loch on it". ) Dick Francis published his autobiography The Sport of Queens the following year, worked as the racing correspondent of the Sunday Express for 16 years and wrote two stablefuls of successful thrillers in conjunction with his late wife Mary. If ever there was the proverbial good career move in disguise, his mishap on Devon Loch was it.

The Queen Mother lived to drink many another gin and tonic and reach a ripe and immensely popular old age. To the Royal Ascot lunch marking her 400th winner she invited none other than Dave Dick, who died five years ago, as guest of honour.

Devon Loch himself broke down at Sandown in January 1957 and was retired. Sundew went on to win that year's Grand National. Fred Rimell would train three more winners of the race.

Toss Taaffe, Tom's uncle, is alive and well and living in Rathcoole, County Dublin.

One hopes, meanwhile, that Georgi Malenkov enjoyed his day at Aintree; Malenkov would . . . that occupational hazard of Soviet politics . . .eventually fall foul of the Politburo, be exiled and end up running a hydroelectric plant back home in his native Kazakhstan.

At least he had one good yarn from his visit to the capitalist West to regale the comrades with to the end of his days.

1956 AINTREE GRAND NATIONAL 1 ESB (D Dick) 11-3, 100/7 2 Gentle Moya (G Milburn) 10-2, 22/1 3 Royal Tan (T Taaffe) 12-1, 28/1 4 Eagle Lodge (A Oughton) 10-1, 66/1 Winning trainer TF Rimell 29 ran, 9 finished Distances 10 lengths, 10 lengths Time 9 minutes 21 seconds Value to the winner £8,695 5s 0d