Duke & Duchess Of Cambridge And Prince Harry Attend St Symphorien Miltary Cemetery

MONS, BELGIUM - AUGUST 04: (L-R) Belgian outgoing Prime Minister Elio Di Rupo, British Prime Minister David Cameron, Queen Mathilde of Belgium, King Philippe of Belgium, Prince William, Duke of Cambridge and his wife Catherine, Duchess of Cambridge and Prince Harry attend a ceremony at St. Symphorien Military Cemetery on August 4, 2014 in Mons, Belgium. Monday 4th August marks the 100th Anniversary of Great Britain declaring war on Germany. In 1914 British Prime Minister Herbert Asquith announced at 11pm that Britain was to enter the war after Germany had violated Belgium's neutrality. The First World War or the Great War lasted until 11 November 1918 and is recognised as one of the deadliest historical conflicts with millions of casualties. A series of events commemorating the 100th Anniversary are taking place throughout the day. (Photo by Francois Lenoir - Pool /Getty Images)