Aidan O'Brien will saddle a three-strong team at this year’s Qatar Prix de l’Arc de Triomphe, while his son Joseph will also be seeking glory in the European middle-distance championship.
Aidan's trio included Prix de Diane heroine Diamond Necklace, Irish Derby champion Benvenuto Cellini and last year’s runner-up Minnie Hauk.
It is 10 years since he last won the Prix de l’Arc de Triomphe with Found.
Diamond Necklace has won both the French 1000 Guineas and French Oaks, while Benvenuto Cellini has taken the Irish Derby and Minnie Hauk was a dual Oaks winner last season and runner-up in the Arc.
"We’re happy with them all, we hope they have chances but it’s very competitive. The ground is a little on the soft side this morning so it will be interesting to see what the ground is like," O’Brien told Sky Sports Racing on Thursday afternoon.
"I think the only question is the distance with Diamond Necklace. We could have run her in the Vermeille at the distance, but the thinking was we wouldn’t because if she struggled at the distance then come Arc time she could be a little bit empty.
"So we decided to stay at a mile and a quarter, we didn’t train her very hard, the ground got very bad and patchy and we probably underestimated Christophe’s (Ferland) filly (Aventure) who was in very good form.
"She’s in good form, will she get a mile and a half? We can’t be sure. Her dam stayed a mile and a quarter well, but never went up in trip, there is plenty of mile and a half in her family so it will be interesting.
"There’s things like stride length, her heart rate, the way she settles that give you an indication and all those suggest she could, but still you can never be sure."
Minnie Hauk’s season has been underwhelming after an almost perfect 2025, but O’Brien believes there have been genuine excuses.
He said: "We decided we would train her for the race this year, but she has had plenty of little problems with corns in her feet and we’ve not had a good run at her with any race this year.
"This was always the race we had in our minds so we were never going to over-train her anyway.
"We were very happy with her the last day but because the pace was so slow she was back too far. It will be interesting, she wasn’t beaten very far last year.
"We think she’s at the same level as last year, but obviously her form is not as good. We think she’s in good shape, but could you be as confident as last year? Probably not, but there’s been reasons for her getting beat."
Benvenuto Cellini was a relatively late addition to the team when it transpired the ground would be decent.
"We were happy with him in the Niel, we had a pacemaker and we just didn’t follow him," said O’Brien.
"He’s a high-pace horse, long striding and the pacemaker got away and that just meant it was an ordinary pace which didn’t suit, but he did come home well.
"At that time our horses were running ordinary so he could leave that run well behind, he’ll like the ground. We didn’t think he’d be running because we didn’t think the ground would be like this.
"We found that low-grade infection after his last run that was running through them, we medicated them and since then our horses have been running better recently.
"We’re not sure who rides what, Ryan (Moore) will decide after the draw and we’ve got Christophe (Soumillon) booked. It’s not straightforward, we know Minnie and Benvenuto stay but we’re not sure about Diamond."
His son Joseph will rely on Oaks winner Thundering On after she returned to winning ways at the Curragh recently.
The Irish contingent feature among 16 declarations for Sunday’s marquee event headed by Francis-Henri Graffard’s ParisLongchamp specialist and defending champion Daryz.
There will be dual Japanese representation as Admire Terra and Meisho Tabaru attempt to dethrone Daryz.
Many will remember Orfevre’s agonising near-miss for Japan in 2012 before finishing second again when bumping into Treve in 2013. Leading the quest to end a losing run dating back to 1969 is Takarazuka Kinen hero Meisho Tabaru, who will be ridden by his nation’s most decorated jockey, Yutaka Take.
"Meisho Tabaru has often had a lot of time between his races," said trainer Mamoru Ishibashi, who sends the five-year-old to France fresh.
"We considered running in a prep race, but we felt there was no problem with going directly to the Qatar Prix de l’Arc de Triomphe after the Takarazuka Kinen."
He will be joined in the race by Admire Terra, who bids to make it third-time lucky for trainer Yasuo Tomomichi who has previously saddled Makahiki to finish 14th in 2016 and Do Deuce who was 19th in 2022.
"This year we really looked for a horse who might be better able to adapt to Longchamp," said Tomomichi, who has booked dual Arc winner Cristian Demuro for steering duties.
"Among the horses we had available, Admire Terra seemed to us to be the best candidate.
"The Qatar Prix de l’Arc de Triomphe is a race I dream about. No Japanese horse has ever won it. It is a very special race for all Japanese people. If I could become the first Japanese trainer to win it, it would be a dream come true."
Daryz is one of four French challengers alongside Graffard-trained stablemate and Prix Niel winner Varandir, Alicja Karkosa’s Chestnut Rocket and Arrow Eagle who aims to send Jean-Claude Rouget into retirement on a high.
John and Thady Gosden’s Friendly Soul has the chance to enhance her fine course record after the Prix Vermeille winner was added into the race for free on Wednesday, while others from Britain are George Scott’s Bay City Roller and Roger Varian’s Saddadd, a Group One winner in Baden-Baden last month, Maltese Cross (William Haggas) and Kalpana (Andrew Balding).
Completing the field is German contender Bright Light, third to Saddadd in the Grosser Preis von Baden most recently.
