Will Diamond Necklace write her name into the history books and secure Aidan O'Brien more Classic glory in Prix de Diane?

Click here to add us to your Google preferred sources or find out more here

Diamond Necklace will attempt to become the first filly trained outside France to achieve a significant treble, while keeping up the relentless pace achieved by Aidan O'Brien with his three-year-olds this Classic campaign. 

The daughter of St Mark's Basilica has last season's Prix Marcel Boussac and the Poule d'Essai des Pouliches on her CV and, were she to add the Prix de Diane Longines, she would join Allez France, Divine Proportions, Zarkava and Blue Rose Cen in having completed that trio of Group 1 victories.

O'Brien already has four of the six major European Classics over a mile to his name, as well as the Epsom and Chantilly versions of the Derby, and will be hoping Diamond Necklace can earn him a second Diane, as well as a first win in the race for Ryan Moore. 

"Everything has gone well with Diamond Necklace and we've been very happy with her," said O'Brien. "The plan was always if everything went well in the Guineas to come here. We've always thought a mile and a quarter shouldn't be a problem to her. 

Diamond Necklace, Green Spirit (white cap) and Esna (purple sleeves) all reoppose from the Marcel BoussacCredit: Edward Whitaker (racingpost.com/photos)

"She's very like her sire [St Mark's Basilica], and when he went up to a mile and a quarter he improved again. Everything she does is very like him."

Wayne Lordan rides Moments Of Joy, of whom O'Brien said: "She ran in the Musidora at York. They went a little bit steady for her but she ran okay. We think she'll like the trip and she'll like the track as well."

Analysis: neither trip nor ground is likely to beat Diamond Necklace, so we're looking for a superior talent

Barring a major drift on the day, Diamond Necklace is set to be sent off the fifth odds-on favourite in the Diane this century and, while she is unlikely to rival the 1-3 at which Zarkava was returned in 2008, she could challenge the 8-15 winning SP of Divine Proportions. 

The other two fillies to go off at shorter than evens – Beauty Parlour (2012) and Volvoretta (2000) – finished second. 

Those keen to take on Diamond Necklace will point to the fact that her wins in the Marcel Boussac and the Poule d’Essai came on much slower ground than the expected good to firm, although her first two wins last year came on good and good to yielding.

On breeding you could argue that her Group 1 victories at a mile have been a bonus, her stellar pedigree positively shouting improvement over middle distances. 

Evolutionist (checked sleeves) chased home True Love in the 1,000 GuineasCredit: Alan Crowhurst (Getty Images)

Evolutionist has Classic form in the book and is another who may find improvement at this trip, for all that Karl Burke hinted during the week that her work has caused a tinge of regret about taking her out of the Coronation Stakes over a mile at Ascot. 

Green Spirit put up an extraordinary performance to come third in the Poule d’Essai when compromised by a wide draw, actually running a faster closing three furlongs than Diamond Necklace, so she has claims if seeing out the trip. 

Then there is the prospect of a challenge emerging from one of the British Classic trialists. 

Felicitas had the form of her Musidora second boosted by Legacy Link in the Oaks and looked to stay the trip fine at York, for all her family is essentially one of fillies who didn’t get much further than a mile. 

The daughter of a Breeders' Cup Filly and Mare Turf winner, Lilt looked more than ready for a step up in distance when overcoming a flat spot to power clear in the Listed Michael Seeley Memorial. 

David Menuisier is convinced that Inis Mor didn’t run her race in the 1,000 Guineas. She showed much more spark when picking up well in the Height Of Fashion. 

Inis Mor and Saffie Osborne (nearside) beat Earth Shot in the Fitzdares Height Of Fashion StakesCredit: Edward Whitaker (racingpost.com/photos)

And perhaps as intriguing as any of them is Esna, who was not beaten that far by Diamond Necklace and Green Spirit in the Boussac, and who bounced back from finishing fourth in the Pretty Polly when showing great resolution to battle past Sacred Ground at Newbury. 

All four will need to take a major step forward to trouble an on-song Diamond Necklace, but each has shown enough promise to suggest it’s far from impossible.

What They Say

Karl Burke, trainer of Evolutionist
We can ride her a little differently. I am sure she will stay the trip and will be able to show a turn of foot at the end of it. But we will not ride her as aggressively as we did in the Guineas. Diamond Necklace looks hard to beat, but she will be racing on different ground from last time.

Yann Lerner, joint-trainer of Evita
Her run in the Saint-Alary wasn't too bad despite the fact she wasn't in love with the soft ground. She struggled to get balanced and was on the wrong leg at one stage, but she still ran a good race. We have faith in the filly and she will love the quicker ground.

Brian Meehan, trainer of Esna
I'm very pleased with her and she's done very well since Newbury. From the Boussac the Diane was always the target, so we're on course. Newbury is a lovely big galloping track and she wasn't stopping, so I've got no issues with her stamina.

David Menuisier, trainer of Inis Mor
She did what she had to do at Goodwood and she came out of the race beautifully. It was here or the Ribblesdale and the way she won at Goodwood, I can't say she's crying out for a trip at this point of her career. She has a squeak.

Felicitas (orange cap) lays it down to Legacy Link in the Musidora at YorkCredit: Edward Whitaker (racingpost.com/photos)

Ed Walker, trainer of Felicitas
We've always thought she was a good filly and she proved it in the Musidora at York, even though she was outstayed by Legacy Link. The strength of the form was underlined when the winner was a good second in the Oaks last week, beaten only by an exceptionally good filly [Thundering On].

Christopher Head, trainer of Green Spirit
I think this kind of distance is within her range. The draw can have a big effect on a race and that was certainly the case in the French Guineas. She has a good draw. I'm very happy with the filly and everything has gone according to plan.

William Haggas, trainer of Lilt
She has plenty of ability but is short on experience having run and won twice. She hit the line strong at York last time, which suggested this trip would suit her. The fast ground should not be a problem. She's not got a great draw in stall ten but she's not on the wing, so hopefully she can run a nice race.

Read more:

'She's done really well physically' - Shane Foley backs 1,000 Guineas runner-up to go one better in Sunday's Prix de Diane 

'Shane Foley was very taken with her' - Karl Burke looking to Evolutionist to put it up to Diamond Necklace in Prix de Diane 

'She’s not going for the day out' - William Haggas aims Lilt at Prix de Diane as Diamond Necklace heads 17 remaining entries 

Looking for free bets? Racing Post have got the best offers, all in one place. Visit racingpost.com/freebets to find out more.