Aidan O'Brien produced one of the most tactically calculated performances of his storied training career on Sunday, sweeping the podium in the 186th running of the Qatar Prix du Jockey Club at Chantilly — a Group 1 result that will be studied for years as a masterclass in race management and stable depth.

The Race

Constitution River, a son of Wootton Bassett bred in Normandy by Gérard Laboureau's LG Bloodstock operation at Haras du Cadran, won the race under Ryan Moore in a time of 2:03.52 — the third-fastest in the history of the event, behind Ace Impact's 2:02.63 in 2023 and Sottsass's 2:02.90 in 2019. Hawk Mountain, also by Wootton Bassett, finished second under Christophe Soumillon, with Montreal third under Wayne Lordan. The trio finished well clear of the remaining thirteen runners, with Donnacha O'Brien's A Boy Named Susie fourth and Mikel Delzangles' Alam — the first French-trained finisher — fifth.

Constitution River started favourite at 3.4/1 despite drawing stall 15 of 16. No winner had emerged from that barrier since the race was shortened in distance in 2005. Until Sunday.

The Strategy

When the draw was made on Thursday, O'Brien moved immediately to neutralise the disadvantage. He instructed Lordan and Soumillon to push forward from the gates and control the tempo, freeing Moore to settle Constitution River wide and alone on the outside before threading him into the first three. O'Brien also walked the track personally beforehand, as is his established practice, to identify the best ground. The result was three O'Brien runners dictating the race from the front, moving as a unit into the home straight before quickening clear of the field in the final 400 metres.

Lordan, controlling the pace on Montreal along the rail, held on long enough to believe he might win. Soumillon challenged first on Hawk Mountain and briefly entertained the same thought. But Constitution River's superiority on the outside was decisive. Moore's assessment afterwards was measured but telling — the horse, he said, does everything effortlessly, has speed, stays well, and carries an excellent temperament. "When a horse is that straightforward," Moore noted, "the draw becomes less important than it otherwise might have been."

Historical Context

O'Brien has filled the Chantilly podium before. In 2016, when the Qatar Prix de l'Arc de Triomphe was temporarily run at Chantilly during Longchamp's redevelopment, Found, Highland Reel and Order of St George finished one-two-three for the stable. Co-owner Michael Tabor drew the connection himself after Sunday's race, noting that a similar result had been achieved on the same track a decade earlier.

For O'Brien, this is also his third Qatar Prix du Jockey Club victory, following St Mark's Basilica in 2021 and Camille Pissarro in 2025. Moore recorded his third win in the race as well, having also partnered Camille Pissarro last year and The Grey Gatsby in 2014. The win gave Wootton Bassett his second success in the race in as many years, with Camille Pissarro having been his first.

For Haras du Cadran — the Normandy operation owned by Pierre Talvard where Constitution River was born and raised — the victory carries its own distinction. The stud has now produced two Qatar Prix du Jockey Club winners since the 2005 distance change, making it the only commercial breeding operation to achieve that feat. Constitution River was purchased by the Coolmore partners, the ticket signed by M.V. Magnier, for €400,000 at the August 2024 Arqana Yearling Sale.

What Comes Next

O'Brien was characteristically measured about future targets. He flagged the Eclipse Stakes as a possibility if the horse comes through Sunday's effort well, while also floating an autumn return with an Arc trial in mind. Moore went further in suggesting Constitution River could drop back to a mile or step up to a mile and a half — a range that, if accurate, would position him as a versatile high-end performer for the second half of the season.

Donnacha O'Brien expressed genuine confidence in A Boy Named Susie despite the fourth-place finish, stating plainly that he believes the horse is capable of winning at Group 1 level. The Eclipse Stakes was mentioned as a potential next step for him as well — which may yet set up a compelling rematch with the horse that beat him on Sunday.

O'Brien saddled eight colts across Chantilly and Epsom on the same afternoon, splitting the squad between the two races. That four of them filled the top four positions across a Classic field of sixteen — with the other four running at Epsom — speaks to a depth of talent that makes the rest of the European middle-distance season look, at this moment, very much like his to lose.