LONDON, ENGLAND - MARCH 09: Guests including Prince Harry, Jeremy Corbyn, Princess Anne, the Princess Royal, Camilla, duchess of Cornwall, Prince Charles, Prince of Wales, Queen Elizabeth II, Prince Phillip, Duke of Edinburgh, Teresa May and Michael Fallon, Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge, Phillip Hammond, Sophie, Countess of Wessex and Prince Edward, Earl of Wessex attend the dedication service of The Iraq and Afghanistan memorial at Horse Guards Parade on March 9, 2017 in London, England. (Photo by Stuart C. Wilson/Getty Images)

LONDON, ENGLAND - MARCH 09:  Guests including Prince Harry, Jeremy Corbyn, Princess Anne, the Princess Royal, Camilla, duchess of Cornwall, Prince Charles, Prince of Wales, Queen Elizabeth II, Prince Phillip, Duke of Edinburgh, Teresa May and Michael Fallon, Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge, Phillip Hammond, Sophie, Countess of Wessex and Prince Edward, Earl of Wessex attend the dedication service of The Iraq and Afghanistan memorial at Horse Guards Parade on March 9, 2017 in London, England.  (Photo by Stuart C. Wilson/Getty Images)