The Festival of British Eventing, presented by the British Equestrian Trade Association (BETA), at Gatcombe Park, the home of HRH The Princess Royal, has attracted a record entry of more than 100 horses from 10 nations.
New Zealand has a good record at Gatcombe, and the field includes Olympic riders Andrew Nicholson, with Spanish full-brothers Armada and Nereo; Mark Toddand Gandalf; Caroline Powell with Lenamore, and Joe Meyer and Ariki.
The field also includes four French riders, headed by Pascal Leroy with two horses and former World Champion Jean Teulere, for whom it is a first opportunity to qualify for the HSBC FEI World Cup Eventing Final at Strzegom, Poland, later this month.
The competition will also decide the national eventing title, an accolade which Mary King and William Fox-Pitthave won a record five times apiece.
King will ride Imperial Cavalier, third at Tattersalls, Ireland, and her team horse at the HSBC FEI European Eventing Championship in September, plus her home-bred mare Kings Temptress and Apache Sauce.
Fox-Pitt has Macchiato, fifth at the Mitsubishi Motors Badminton Horse Trials, and Navigator, while their team mate Kristina Cook will be trying to take the title for the first time on her Olympic bronze medalist Miners Frolic.
The Irish will use the festival as a final trial for Fontainebleau; they have eight riders entered, including Patricia and Michael Ryan, who scored such a memorable family one-two at Tattersalls.
Australia, too, is well-represented, with defending HSBC FEI World Cup Eventing Champion Clayton Fredericks on Ben Along Time and Poilu and his wife Lucinda with her Rolex Kentucky Three-Day Event winner Headley Britannia.
The Festival of British Eventing was added to the HSBC FEI World Cup Eventing calendar after the cancellation of Chatsworth, and will run in its traditional format climaxing with the reverse-order Cross-Country phase around Captain Mark Phillips's spectacular course up and down the Gatcombe valley.
• Bruce Davidson, a famous winner at Gatcombe Park back in the 1980s on the great JJ Babu, competes the other side of the Pond this weekend, in the HSBC FEI World Cup Eventing qualifier at Mansfield, Ontario.
He rides his lovely grey mare Jam plus the Irish-bred Cruise Lion, 19th at the Rolex Kentucky Three-Day Event in April, while his son Buck has the much-admired My Boy Bobby, third there, plus In The Beat.
The 33 entries for the event at Wits End Farm, an enterprise started in 2002 by Jo Young and Bill McKeen, also include dual Olympic gold medallist Phillip Dutton with Tru Luck and Woodburn, 12th at Kentucky.