The pair were crowned European eventing champions at Blenheim in 2005, and will return to the site of their victory to show off for fans.
Zara and Toytown will be heading a “parade of champions” as part of Blenheim’s 25-year anniversary celebrations on the Sunday afternoon of the event (20 September).
“We are delighted to have Toytown and Zara at Blenheim this year,” said event director Mandy Hervieu.
“Toytown is one of the most famous, best-loved event horses of all time and we hope that spectators will enjoy the chance to see him once more.”
The chestnut gelding with distinctive markings was a popular figure in the eventing world.
Toytown is now 22 and spends his retirement at Zara’s Gloucestershire based. He was retired at Gatcombe in 2011.
“Toytown is my horse of a lifetime and he has given me more than I could ever have dreamed of,” Zara said at the time.
Known as “Noddy”, the gelding moved to Zara as a seven-year-old.
The pair won the under-25 championships at Bramham in 2002. They then finished second at Burghley in 2003 and two years later Zara made her senior team debut, winning individual and team gold on home ground at the Blenheim Europeans. She and Toytown followed this up by claiming the world title and team silver at Aachen in 2006.
Sadly due to injury he was unable to contest an Olympics, missing Athens 2004 and Hong Kong 2008.
Zara, who is hoping to be part of Britain’s team at the Rio Olympics in 2016, will be competing at the Oxfordshire event in the CIC3* class for eight-and-nine-year-olds.
She will be riding Watkins, a nine-year-old thoroughbred gelding, who started his career in New Zealand and joined Zara’s team this year.
The pair finished eighth in their first CCI2* at Camphire in Ireland recently and this will be their first attempt at three-star level.
Picture by Kit Houghton