Aidan O’Brien relies on Japan to provide him with a fourth victory in the Prince of Wales’s Stakes at Royal Ascot on Wednesday.

It is 12 years since the Ballydoyle handler first claimed the 10-furlong contest with Duke Of Marmalade, since when he has added to his tally with So You Think (2012) and Highland Reel (2017).

Japan enjoyed an excellent three-year-old campaign last season, recording big-race victories in Royal Ascot’s King Edward VII Stakes, the Grand Prix de Paris and the Juddmonte International, before rounding off with a fourth-placed finish in the Prix de l’Arc de Triomphe.

The son of Galileo is a warm order to dispatch of six rivals in the hands of Ryan Moore.

O’Brien said: “What he did in the Juddmonte, he looked comfortable enough and he’s a horse that never does too much anyway.

“He doesn’t overdo himself. He’s very comfortable at a mile and a quarter and he does a mile and a half as well. He’s very versatile.”

Disputing second-favouritism for a race that forms part of the Qipco British Champions Series are the Charlie Appleby-trained Barney Roy and Roger Charlton’s Headman.

Barney Roy was impressive in winning two lucrative prizes at the Dubai Carnival earlier in the year and already has a Royal Ascot victory to his name, having landed the St James’s Palace Stakes for Richard Hannon in 2017 before an unproductive spell at stud.

Appleby said: “His previous two starts this year were over nine furlongs in Dubai, but I’ve always felt that stepping him up in trip would bring about more improvement.

“I know he’s been over the trip before, in the Eclipse and Juddmonte International (in 2017), but for me he’s an older and stronger horse than he was then.

“On the back of his runs this year, I think he goes there in good shape and we are looking forward to going back to Ascot with him, where we know he’s been a past winner at the Royal meeting.”

Headman won a valuable Newbury handicap and a couple of French Group Twos last season, before finishing fifth in the Irish Champion Stakes at Leopardstown last September.

Teddy Grimthorpe, racing manager to owner-breeder Khalid Abdullah, told Sky Sports Racing: “Roger has always thought highly of him. He’s a nice, scopey horse now. He’s done very well through the winter.

“His two best races were both in France last year. He’s a got a bit of class, slightly like his father, Kingman – he has that good turn of foot to go and win.

“He obviously needs to step up and win at Group One standard this year. He’s given us the right signs he’ll be better as an older horse, but he has it put it on the line.”

John Gosden saddles a couple of runners at double-figure odds in Lord North and Mehdaayih.

Lord North won his fifth race from just eight career starts when landing the Brigadier Gerard Stakes at Haydock recently, while Mehdaayih has always been held in high regard.

“Lord North is a grand horse and he’s taking his chance. It’s a good edition of the race,” said Gosden.

“He did nothing but improve last year. He won a Cambridgeshire doing handstands and two Listed races. We could have run him in the Listed race (Wolferton) with his penalty, but that seemed a little bit cowardly – we thought it’s a small-enough field, it’s a lovely race to run in. We’d be thrilled to get a piece of it.

“Mehdaayih is a very talented filly. We deliberated and waited. I didn’t want to run her before this. She’s not a huge, strong filly, she’s very athletic and I think she’ll go there well fresh.”

Proven mud-lover Addeybb has already enjoyed a profitable year for William Haggas and Tom Marquand after winning a pair of top-level prizes in Australia.

Haggas said: “We were pleased to see the rain falling on Monday evening and the more that falls between now and Wednesday afternoon the better for him.

“He’s ready to go. He’s had a good year already and he came back from Australia very fit.

“This is probably a bit of a step up from the Australian races, but he’s no slouch and a pretty smart horse on his day.”

The field is completed by Andrew Balding’s Bangkok, who returns to turf action following an odds-on defeat in the Winter Derby.