Britain's Prince William, Duke of Cambridge (L) and Britain's Prince Charles, Prince of Wales arrive for the Order of The Garter Service at St Georges Chapel, Windsor Castle in Windsor, west of London on June 13, 2016.
The Order of the Garter is the oldest and most senior Order of Chivalry in Britain, established by King Edward III nearly 700 years ago. / AFP / POOL / Matt Dunham        (Photo credit should read MATT DUNHAM/AFP via Getty Images)