Why Princess Anne Wears Military Uniform But Catherine and Camilla Don't Princess Anne will appear on horseback in the The King's first Trooping the Colour parade, and will be wearing a military uniform – but despite having ties to the military, Queen Camilla and Kate won't be joining her Princess Anne wears a military uniform at many royal events This year's Trooping The Colour is set to be one for the history books – it not only marks the first of King Charles III's reign, but hit will also be the first time a reigning monarch will ride at the annual parade since 1986, when Queen Elizabeth II last rode. The King will today (Saturday, June 17) take to the streets of London alongside his son, the Prince of Wales, and will also be joined by his sister, Princess Anne. The public have become accustomed to seeing the late Queen Elizabeth's only daughter on horseback – usually decked out in her military uniform along with medals and badges. Princess Anne hasn&