Horses like Double Trigger and Celeric, who finished a noble fourth yesterday, have transformed the marathons from embarrassing throwbacks into compelling centrepieces in no more than half a dozen seasons.
Now a new generation seems ready to inherit their legacy, led by the four-year-old Enzeli, and other gutsy fighters like Invermark, yesterday's runner-up. Nedawi, last year's St Leger winner and the beaten favourite yesterday, may yet be a match for them in time, while Kayf Tara, the Gold Cup winner 12 months ago and third this time, is still only five.
These horses and more will be back for seasons to come, pulling in racegoers not just at Ascot but at Goodwood, York and Doncaster too. They will all do well to cope with Enzeli, though, who was running yesterday for just the eighth time, and must surely get better with age.
The field of 17 was the largest in Gold Cup history, but Enzeli showed everything you could ask of a stayer to beat them off with ease. He travelled smoothly as Murtagh, the Irish champion jockey, took the inside line throughout the first two miles, and quickened instantly to take a decisive lead over a furlong from home. He then lasted out the 20th and final furlong with real determination as Invermark came after him all too late.
The winning colours, those of the current Aga Khan's grandfather, had not been seen on a racecourse for eleven years. That track was Epsom, on the first Wednesday in June 1988, when Kahyasi carried the green and chocolate silks to victory in the Derby. Yesterday, one of Kahyasi's sons did them every bit as much credit.
The cheers were muted as Enzeli passed the post at 20-1, but his Irish connections had not arrived without hope. "He had to improve by 10lb at least to be in the frame, but he has been giving all the right signals recently," John Oxx, his trainer, said.
"He is normally a lazy worker but his work has been very good recently and this extra distance can improve a horse a lot. I don't know whether he will go for the Goodwood Cup or have a break instead, but he will probably go for the Prix du Cadran later on."
It was only good fortune which kept Enzeli with Oxx long enough to win a Gold Cup. "This race is not normally one I have on my agenda," he said, "because I do not have a lot of older horses, they are usually sold. In fact a lot of people could have bought Enzeli last year but he just had one or two little things go wrong."
It would take a wild offer now to prise Enzeli away from his trainer, and the Aga Khan is hardly a man who needs the money. Instead, he should become a familiar feature of the Flat racing landscape, which certainly needs a few more heroes who stick around.
The defeat of Nedawi in the Gold Cup was excellent news for bookmakers, who had already seen Frankie Dettori, his jockey, win the first two races. There was never any danger that Dettori might repeat his through-the-card trick of two years ago - he did not have a ride in the fifth - but the Italian's name in conjunction with Ascot can still cause bookies to develop a nervous twitch.
Both of Dettori's winners were horses of promise, particularly Warm Heart, who took the Norfolk Stakes and now heads to the Richmond at Goodwood, a lightning-fast track which should suit him well. Fairy Queen, meanwhile, who won the Ribblesdale Stakes, will be winning again now that Godolphin can be sure she stays 12 furlongs.
The only horse who really mattered yesterday, though, was Enzeli. "When will those colours be out again?" someone asked the Aga Khan in the winners' enclosure. The Aga smiled and narrowed his eyes. "You must be a punter," he said. "I will be the next time I see those colours," came the reply. Wise man.