Stradivarius will face nine rivals as he goes in search of a fourth Gold Cup at Royal Ascot on Thursday.
John and Thady Gosden's stayer is one of the most popular horses of recent years and would equal a record set by Yeats, who won four successive Gold Cups between 2006 and 2009.
John Gosden said ahead of another leg of the Qipco British Champions Series: "It's great to have him still running so well at this level. He's won the Yorkshire Cup this year, and let's hope he goes and puts in a big one at Ascot.
"In Flat stables you don't normally have horses around for as long as he's been with us. They are usually moving on at three, four or five.
"He's very vociferous, shouting and playing about, but he's got a good mind, he's tough, and he enjoys his training. He's a very fun and enjoyable horse to train, and you can't say that about all of them.
"It's down to the horse. When you have one with the soundness, the heart, the constitution and the mind you are lucky, and you just go with it. It's not so much down to the trainer – it's down to the trainer clocking what he's got."
Alan King has declared his multiple Group One winner Trueshan, despite a heatwave set to hit Ascot this week. King has expressed doubts about the ground, saying on Sunday: "We might hang on in there, but if the forecast is right, I can't see us running."
Kyprios, trained by Yeats' handler Aidan O'Brien, represents the biggest danger to Stradivarius according to the market.
Denied a run at the meeting 12 months ago when he became upset in the stalls ahead of the Queen's Vase, Kyprios has won the Vintage Crop and Saval Beg Stakes this season.
Princess Zoe, runner up last season, has another crack for Tony Mullins while last year's St Leger runner-up Mojo Star has his first run over two and a half miles for Richard Hannon.
Alignak, Earlofthecotswolds, Tashkhan, Bubble Smart and Burning Victory complete the field.
William Haggas' Sea Silk Road is likely to go off favourite for the Ribblesdale Stakes in the absence of Oaks runner-up Emily Upjohn.
She got going late to win a Listed race over 10 furlongs at Goodwood last time out and looks sure to be suited by going up in trip.
O'Brien runs History with Magical Lagoon representing Jessica Harrington. Life Of Dreams, Mukaddamah and Mystic Wells also go in a field of six.
There are 11 in the Group Two Norfolk Stakes, headed by O'Brien's The Antarctic, winner of both his starts to date.
Richard Fahey's Clearpoint, a strong fancy having won his only start in hugely impressive fashion, was ruled out of the race on Tuesday morning. Fahey instead relies on The Ridler.
Walbank, Brave Nation, Bakeel and the filly Pillow Talk all run.
The Queen's Reach For The Moon faces just five in the Hampton Court Stakes.
Once favourite for the Derby, he was second in the Heron Stakes on his delayed comeback this season.
Claymore, Cresta, Howth, Kingmax, Maksud complete the list.
Andrew Balding's Berkshire Rebel shares top weight for the King George V Handicap but he does have red-hot apprentice Harry Davies taking 5lb off his back.
Power Of Beauty and Mr McCann top a maximum field of 30 in the Britannia, while Balding fields Oo De Lally and another Royal runner in Tactical in the Buckingham Palace Stakes.
