Kyprios is out to regain his crown in the Gold Cup at Royal Ascot.

The Aidan O’Brien trained six-year-old beat Mojo Star by half a length to win the 2022 renewal, but was absent last year as he was restricted to just two runs by injury and finished second in both of those races, including when beaten a neck by the reopposing Trawlerman in the Long Distance Cup.

But this season he has shown a return to the type of form that saw him win six out of six as a four-year old.

He has beaten Queenstown twice as a long odd-on favourite over a mile and three-quarters at Navan and Leopardstown and the step back up to two and a half miles will hold no fears for the son of Galileo.

O’Brien said: “Kyprios is a hardy horse and everything has gone well with him, he’s training well and seems in good form. He’s an unbelievable horse and to have him back to this pitch, we’re delighted really.

“I don’t think there is any worries about the ground and I always thought he wanted nice ground, he’s a very good mover.”

Victory for David Menuisier’s Caius Chorister would cap a remarkable career trajectory for his five-year-old mare.

The daughter of Golden Horn won off a handicap mark of 53 at Yarmouth as recently as May 2022 before working her way up to Group race territory over the last eight months.

She landed the Group Three Prix Belle de Nuit in France in October before being headed in Gold Cup trials at Ascot and Sandown by Coltrane and Sweet William respectively, both times when conceding a 3lb penalty.

“She’s been unbelievable from the start, because she’s never really shown much on the gallops and she’s not the prettiest, although we love her, don’t get me wrong. She’s so tough and she always turns up,” Menuisier told the British Champions Series.

“The only race she’s disappointed was when the lad who rides her at home was away following a family bereavement, so perhaps she was grieving too. She didn’t win last year until Saint-Cloud in October, but I think she was extremely unlucky in the Ebor.

“She’s amazing and I take my hat off to her every morning when she walks past. She’s a street fighter. Whatever happens we’ll enjoy the day, but I’m keeping everything crossed that she can win the race, not for me or for Clive (Washbourn, owner) but for her.

“It would be fantastic if she could strike at Group One level after working her way up from 53.”

Gregory represents Wathnan Racing who won the race last year with the currently sidelined Courage Mon Ami.

Gregory won at the meeting last season in the hands of Frankie Dettori when landing the Queen’s Vase and he warmed up for this race with his only appearance this season when third to Giavellotto in the Yorkshire Cup during the Dante Festival.

Richard Brown, racing adviser to Wathnan, is confident Gregory can stay the course over a distance five and a half furlongs further than he has ever run before.

“We were delighted with York and thought it was a great prep for this, I thought he was finishing off strongly.

“It was amazing for Wathnan to win this race last year in what was really their first few weeks of ownership and it’s amazing to be going back with a colt with another chance.

“It’s a very tough race and Kyprios is a worthy favourite, but there’s others in there to worry about as well. Hopefully he can be a good substitute for Courage Mon Ami.

“I think he will stay but you never know until you run them over those extreme distances.

“The one thing James (Doyle) has always said is he has such a great temperament and that is such an asset in those staying races because you have to gallop down the hill and many horses lock on there, and James felt he would just be able to switch him off for two miles and get him into a rhythm and that is so important in those staying races.”

Trawlerman will be hoping to deny Kyprios once again when the pair renew their rivalry over two and a half miles.

It will be the first appearance on British soil for John and Thady Gosden’s charge since defeating his O’Brien-trained rival by a neck on Champions Day in October.

He finished three and a half lengths behind Tower Of London in third in the Dubai Gold Cup in March, with William Buick, who rides the six-year-old for the first time, confident of another strong showing.

“I sat on him for the first time and rode work on him last week, and he’s in great form,” Buick said. “He was a good third in the Dubai Gold Cup and the question with him and a lot of the others is the last half mile.

“I haven’t had much luck in the Gold Cup, but he’d be one of my better rides in it for sure.”