The complexion of that high point of the Summer on the English turf, the King George VI & Queen Elizabeth Stakes sponsored by Betfair (12 fur.), changed abruptly in an instant on Tuesday morning when pre-race favourite St. Nicholas Abbey (by Montjeu) fractured his pastern during morning work at his base, Ballydoyle Stables in Co. Tipperary, Ireland. The six-year-old underwent a lengthy surgery at Fethard Equine Hospital on Wednesday and is reported to have come through it satisfactorily, although there is a long way to go before he recovers enough to stand and graze.

At the time he was injured, the triple Coronation Cup winner was in rousing form, having annexed the prize on both his public appearances this year, although he was somewhat suspect on a right-handed track. Now, of course we will never know if he could have acted equally well while going clockwise in this company.

Despite the unfortunate loss of the race's star attraction, there are several others that rank high in the pecking order of middle-distance stayers in Europe. While the Prix de l'Arc de Triomphe at Longchamp in October usually draws a greater number of runners and tends to be a more international affair, the "King George" is run at a better time of year, when the going is more straightforward. The Arc, often contested in soupy conditions, can be a mess!

A pair of members of the classic generation will take on six older rivals in the £1,000,000 feature, scheduled for 3:50 p.m. local this Saturday, making for a compact field of eight runners.

Having displayed merit far in excess of that shown by any of his nine rivals, Cirrus Des Aigles (by Even Top) would have been considered a "shoo-in" had he been in last year's form. However a series of setbacks have limited his racecourse appearances in 2013 to a solitary endeavour – a somewhat tame effort in the Grand Prix de Saint-Cloud last month. Favoured at 13 to 8 despite that loss, the French challenger from the yard of Mme. Corinne Barande-Barbe gets a new rider in Christophe Soumillon, as the gelding's regular partner, Olivier Peslier, has teamed up with another foreign invader, of which more later.

Explaining that uncharacteristic loss, Cirrus Des Aigles' trainer said: "Since Saint-Cloud he has done exactly what I wanted him to do. He went higher after the race and after each of his little and bigger bits of work and I think he will be very well on Saturday. I think he is as good as ever. I gave him plenty of time and my choice was to wait as long as I could. Even the Grand Prix de Saint-Cloud was a bit short in time, but he was able to go and run and I did. He was probably at 60% for that race. He really needed it because this horse feeds himself on competition."

As the Hillstar team has chosen to supplement that three-year-old into the race, Ryan Moore cannot partner the German ace, Novellist (by Monsun), whom he had ridden to victory in the Grand Prix de Saint-Cloud. In his place, Gutersloh-based handler Andreas Wohler has called upon the services of the in-form Johnny Murtagh, who is flying high this term and who was triumphant astride last week's classic victress, Chicquita, in the Irish Oaks.

The trainer was quite bullish when he said: “Novellist is on target for the King George. He came out of Saint-Cloud really well and is in good form. We have always believed in the horse and he is proving it now. He has to improve a bit further to win at Ascot but he will head there in great shape.”

Should the 4 to 1 second favourite succeed, he would gain the unusual distinction of having scored Group-race victories consecutively in Italy, Germany, France and England at his last four starts. Not many are that versatile or consistent!

Sheikh Hamdan Al Maktoum has a pair of high class middle distance runners, Ektihaam (by Invincible Spirit) and Mukhadram. As the latter is more of a ten furlongs-type, he has been routed to York to contest a Group 2 event over his preferred trip on the same afternoon. Consequently, retained rider Paul Hanagan will not be at Ascot to steer the first-named, and connections have opted for Dane O'Neill aboard the Roger Varian-trained gelding. Ektihaam (7 to 1 here) fell during the running of the Hardwicke Stakes at Royal Ascot last month and if he has recovered from that humiliating experience could well figure prominently.

Very Nice Name (by Whipper) adds a touch of exotic zest to the field as the first Qatari-trained runner to take part in it. The four-year-old won all his starts in Doha during the winter, including the Qatar Derby, and demonstrated his international worth when third to St. Nicholas Abbey in the Dubai Sheema Classic at Meydan in March. Owned by Sheikh Abdullah Al Thani, the colt is schooled by Frenchman Alban de Mieulle, who also runs a satellite stable in France. It is this runner, a 16 to 1 chance, to which Olivier Peslier has been obliged to shift his allegiance.

Universal (by Dubawi) and Red Cadeaux (by Cadeaux Genereux) are the other older horses left in. The former has a great record at the trip, having scored over the mile and a half four times in his last five starts. With Joe Fanning on board for trainer Mark Johnston, Abdullah Al Mansoori's colt has a definite place chance, although a victory might be "a bridge too far". Ed Dunlop's Red Cadeaux, who will have a new rider in Graham Lee, has not scored in England for over a year and his form has been declining over his last four starts which no doubt explains the 33 to 1 readily available. Perhaps age is catching up.

On to the three-year-olds: only two of that age – Alamshar (2003) and Nathaniel (2011) have hoisted a winning flag in this race in the past decade, although in a similar period between 1986 and 1995 eight of that ilk had outpointed their seniors.

Champion English trainer Sir Michael Stoute has gambled on improvement emanating from his ward, Hillstar (by Danehill Dancer), who has something to find on the form book. The course-and-distance winner, last seen triumphing in the King Edward VII Stakes at Royal Ascot, has been supplemented at the enormous cost of £75,000 to try and give Stoute his sixth victory in the King George VI and Queen Elizabeth Stakes. That would take him clear of Maj. Dick Hern and Saeed bin Suroor, who like Stoute currently have five wins apiece in the stellar event. Ryan Moore will be in the saddle on the Rothschild hope, currently available at a best-priced 7 to 1.

The only visitor from the Emerald Isle is Jim Bolger's surprise Dubai Duty Free Irish Derby hero, Trading Leather (by Teofilo). The subject of positive reports from his stable, the 5 to 1 Bolger home-bred has "flourished" since then, according to his connections. The colt is attempting to emulate the feat of a former inmate of his stable in St. Jovite, who completed the second leg of this particular double in 1992 under the guidance of Stephen Craine, a rider who was often seen sporting the famous Goculdas Stable's "Cherry & Black Hoops" silks in India in the 'eighties.

Since then, Craine has retired to his home in Athy, Co. Kildare, and Bolger's retained jockey from the 1993 season onwards has been Kevin Manning, who also happens to be his son-in-law – it is he who will be at the controls this Saturday. Bolger said: "Trading Leather is fine and on course for the King George. It was a first-class performance in the Irish Derby. He ran right to the line in a fast time and came out of the race very well. It gets a bit tougher now he is stepping into open company, but I am hoping he is up to the task. Like St Jovite, he is a good Derby winner and I'm hoping he will continue to progress from here. He doesn't like soft ground but after that he doesn't mind."

The runners with the fewest question marks regarding current form are Novellist, Universal and Trading Leather and this trio should form the core from which the winner should emerge.