WATERLOO, BELGIUM - JUNE 17: Prince Charles, Prince of Wales and his wife Camilla, Duchess of Cornwall, attend the opening ceremony of Hougoumont Farm following its restoration on June 17, 2015 in Waterloo, Belgium. The farm is where British and allied forces successfully held off Napoleon's army during the Battle of Waterloo in 1815. Around 5000 historical re-enactors from around the world will take part in three days of events from June 18, 2015 to mark the 200th anniversary of the Battle of Waterloo. The 1815 battle saw the overthrow of Napoleon Bonaparte and the restoration of Louis XVIII to the French throne. (Photo by Carl Court/Getty Images)