King is followed by William Fox-Pitt on Cosmopolitan II, Charlotte Bathe on The Cool Customer and Kristina Gifford on Midnight Blue. The two other Britons, Nigel Taylor on The Frenchman II and Lucy Jennings on Diamond Pedlar, will compete as individuals against riders from 18 nations.
Charlie Lane, chef d'equipe of the British team, believes that the quiet of the morning will suit King William when he does his dressage test today. The horse tends to get tense if the atmosphere is too electric (as is likely to be the case later in the day) and he therefore fails to produce his best form.
Lane would also like a good cross-country round from the first team horse on Saturday morning - and King William invariably produces one. "That would set us up nicely from a psychological point of view," Lane said.
Riders believe that the steep hills on this lovely venue near Rome will make it a searching test of stamina. "It's half a minute shorter than the course at Badminton, but I think it will be just as tiring," King said. Most people believe that the optimum time will be hard to achieve.
Three non-European nations - Australia, New Zealand and the United States - are also taking part in this event, which is "open" for the first time.