Queen Elizabeth II attends the third day of the Royal Windsor Horse Show at Home Park on May 15, 2004, in Windsor, England. Getty Images
Queen Elizabeth II holds her Fell ponies, Bybeck Nightingale, right, and Bybeck Katie, in her 96th birthday image. Photo: henrydallalphotography.com via Getty Images
Princess Anne helps her mother, Queen Elizabeth II, fit the bridle to the pony Greensleeves, on the grounds of Balmoral Castle, during the royal family's summer holiday in Scotland in 1955. PA Images via Reuters
Queen Elizabeth II rides her horse Burmese, with then US president Ronald Reagan on Centennial, on the grounds of Windsor Castle, on June 8, 1982. Getty Images
Queen Elizabeth II greets her British thoroughbred racehorse, Highclere, in the paddock during the Prix de Diane, on June 16, 1974 in Chantilly, France. AFP
Princess Elizabeth at Sandringham, with a horse, in 1943. AFP
Queen Elizabeth II, Princess Margaret and Prince Edward ride at Ascot Racecourse on June 27, 1968. Getty Images
Queen Elizabeth II meets her racehorse Knock Castle as she attends the King's Troop, Royal Horse Artillery, during their 70th-anniversary parade, at Hyde Park on October 19, 2017 in London, England. Getty Images
Queen Elizabeth II visits the Large Animals Clinical Skills Building at the University of Surrey on October 15, 2015 in Guildford, Surrey, England. Getty Images
Queen Elizabeth II feeds a carrot to the horse Politologue, as trainer Paul Nicholls looks on, during a visit to Manor Farm Stables on March 28, 2019 in Ditcheat, UK. Getty Images
Princess Elizabeth mounted on Winston, a chestnut police horse, in the forecourt of Buckingham Palace, London, in 1949 as part of King George VI's official 53rd birthday. Reuters
Princess Elizabeth in 1935, aged 9. Getty Images
Queen Elizabeth II presents prizes at the Royal Windsor Horse Show on the grounds of Windsor Castle, on May 11, 1991. Getty Images
An undated image of Queen Elizabeth II and Prince Charles riding horses in the park of Windsor Castle. AFP
Princess Elizabeth out riding at the Royal Lodge, Windsor in 1940. Getty Images
