The 2026 Prix de l’Arc de Triomphe is still several weeks away, and the reigning winner is Daryz, who took the 2025 renewal in a close finish from Aidan O’Brien’s Minnie Hauk.
Daryz, trained by Francis Henri Graffard, is back among the entries and heads the early betting for the return to ParisLongchamp on Sunday, October 4th.
That makes him the obvious starting point in the ante-post market, but Constitution River has built a very credible Arc case of his own.
The Aidan O’Brien-trained three-year-old is around 8/1 in the early prices, alongside or just behind stablemate Diamond Necklace depending on the bookmaker, and he has already put together the kind of season that naturally leads to a Longchamp discussion.
Constitution River’s Arc Case
Constitution River has done little wrong in 2026. His French Derby win at Chantilly was his first Group One success, and it was not simply a case of getting the run of the race.
Going off at odds of 12/5 on bookmaker platforms that use the best online betting software, he was drawn 15 of 16, and Ryan Moore had to use him early to secure a workable position.
Yet the colt still had enough left to go clear in the straight and lead home an Aidan O’Brien one-two-three. Hawk Mountain was second and Montreal third.
The win told us a couple of useful things. First, Constitution River can handle French racing and a major away-day assignment. That is not a guarantee that he will reproduce the form at ParisLongchamp, but it is better preparation than heading to the Arc with no experience of the country or its racecourses.
Second, he appeared tactically adaptable. Moore described him as uncomplicated, with enough speed to race handily but the potential to stretch out further if required.
He then strengthened the argument at Sandown in the Coral-Eclipse, where he won by three lengths from A Boy Named Susie, with Hawk Mountain third, having travelled in midfield before moving through the race and going clear inside the final furlong.
It was a 10-furlong race rather than an Arc-distance test, but it confirmed his class against older opposition and showed that he has a turn of foot.
The unanswered question is the mile-and-a-half. The Arc is run over 2,400 metres, roughly 12 furlongs, and Constitution River’s major wins have come over shorter.
His Chantilly performance was over the French Derby trip of about 10 and a half furlongs, while the Eclipse was also over 10 furlongs.
His pedigree, running style and the way he sees out his races give supporters reasons to believe he can stay, but Longchamp in October is a different demand, especially if the ground is testing.
The Leading Rivals
Daryz deserves favouritism on what he has already achieved. Francis Graffard’s colt won last year’s Arc, beating Minnie Hauk in a tight finish, and has remained a high-class performer this season.
He won the Prix Ganay and Prix Aga Khan before finishing third in the Prince of Wales’s Stakes at Royal Ascot. He has proven himself at Longchamp, has the right age profile as a four-year-old and does not have to prove he stays the distance.
Diamond Necklace is the other major Ballydoyle angle. O’Brien’s unbeaten filly won the Nassau Stakes at Goodwood for a fourth Group One success, after which her trainer said an Arc trial could be on the agenda.
Her ability is beyond doubt, although, like Constitution River, she has mainly shown her best over shorter than 12 furlongs. If both go to ParisLongchamp, the stable will have two high-class three-year-olds with different profiles but similar questions over stamina.
Kalpana has a more established mile-and-a-half record. She beat Calandagan in the King George VI and Queen Elizabeth Stakes at Ascot and is among the leading British-trained candidates.
Her seventh in last year’s Arc was not enough to make her a Longchamp specialist, but it at least gives her prior experience of the race. At around 12/1 in one early market, she is an obvious contender if she arrives in the same form.
There are other horses who could alter the picture, including Thundering On, Behrayna, Bay City Roller and Japanese contenders such as Byzantine Dream and Meisho Tabaru.
That is important when considering an 8/1 price in August. Constitution River may be among the leading names now, but the Arc market has plenty of room to move after the September trials and as trainers confirm their plans.
How The Arc Field Takes Shape
The 2026 Prix de l’Arc de Triomphe takes place at ParisLongchamp on Sunday, October 4th, with a start time of 15:05. It is a Group One over 2,400 metres and the field is capped at 24 runners.
France Galop received 73 initial entries when the first stage closed on May 20. Those entries include Constitution River, Diamond Necklace, Daryz and Kalpana, but an entry is not a declaration.
Trainers can still take horses out at the subsequent confirmation and declaration stages, usually because of form, fitness, ground preferences, alternative targets or stable plans.
The race also has routes in through the Arc Races series. Horses that win designated races can gain a Wild Card, assuming they meet the conditions. Those Wild Card winners receive priority if the race is oversubscribed, while the September trials, the Prix Vermeille, Prix Niel and Prix Foy, offer further automatic qualification opportunities.
A horse not originally entered can gain a free supplementary entry through those trial wins, otherwise, a supplementary entry costs €120,000 and the race carries a €5 million purse.
For now, Constitution River looks a legitimate contender rather than an obvious winner. His form is strong, his trainer knows exactly what an Arc campaign requires, and he has already shown he can travel and win at the highest level.
The mile-and-a-half question remains, though, and until he answers it, Daryz is entitled to remain the horse to beat.
