John Gosden hailed Stradivarius as “the most extraordinary and unique racehorse” after the star stayer was retired on Monday.

Gosden, who now trains in partnership with son Thady, has handled the Bjorn Nielsen-owned horse throughout his seven-year racing career, with Stradivarius winning 20 of his 35 starts for the Clarehaven team.

Stradivarius has been sidelined since suffering a bruised foot last month, with the setback forcing him to miss an intended outing in the Lonsdale Cup at York.

That injury has taken longer than anticipated to resolve, resulting in Nielsen’s decision to call time on Stradivarius’ racing career.

A seven-time Group One winner, encompassing three Gold Cups at Royal Ascot and a record four renewals of the Goodwood Cup, Stradivarius will now take up stallion duties at the National Stud.

Gosden said: “Stradivarius has been the most extraordinary and unique racehorse throughout his career. He exhibited joy in his training and has given enormous pleasure to everyone, both on and off the track.

“His constitution has been a marvel to behold and his exciting style of travelling easily in a race, and then quickening to pounce, reflected his character.

“He goes to stud with an amazing race record and enormous affection. To train he has been a complete joy to all of us here. He will remain close to home and is already looking forward to his new career.”

Nielsen believes the time is right to retire his star performer, who ran this year’s Gold Cup hero Kyprios to a neck on what was his final start in the Goodwood Cup in July.

He told Nick Luck’s Daily Podcast: “He took slightly longer to get over that foot bruising that he had when he was withdrawn on the morning of the Lonsdale.

“It would be hard to get him back now for Champions Day and John just thought it would be unfair really to put him through it again as a nine-year-old next year.

“He’s been the soundest horse – he’s never been medicated, he’d never missed an engagement in his career (through injury) and now to start training him with something that’s kind of there that wasn’t there before, it’s time to draw stumps.”

Stradivarius secured the last win of his career at York in May, when taking a third Yorkshire Cup, adding to three Lonsdale Cups on the Knavesmire and two Doncaster Cups.

Frankie Dettori, who rode Stradivarius in all but nine of his 35 outings and was in the saddle for the vast majority of his successes, said in a message posted to Twitter: “I’ve just got the news that the mighty Strad has retired, I’m on my way to Germany to ride Torquator Tasso for the Arc prep.

“What can I say? He’s been a part of my life for the past six years. A good friend, a wonderful horse, so many great times together.

“I’ve never ridden a horse with so many Group wins under my name, I think we did 14 together.

“Big thank you to Bjorn Nielsen and also a big well done to the Clarehaven team.

“It was an honour for me to ride him and I will miss him a lot, he’s been a fabulous horse to have, one of a lifetime. I wish him a happy retirement and hopefully he’ll become a great stallion in the future.”

Nielsen pointed to Stradivarius’ soundness as a key trait and Anna Kerr, chief executive officer of the National Stud, also highlighted the horse’s consistency over a lengthy racing career.

She said: “We are delighted to have a racehorse of the calibre of Stradivarius joining the roster at the National Stud. He has consistently demonstrated many of the attributes that his sire Sea The Stars had, including consistency, soundness and a phenomenal temperament.

“The whole team are looking forward to him arriving here in the coming weeks and he will be available for breeders to view at the stud during the December sales.”