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

MONS, BELGIUM - AUGUST 04: (L-R) Queen Mathilde of Belgium, Catherine, Duchess of Cambridge, King Philippe of Belgium, British Prime Minister David Cameron and Prince William, Duke of Cambridge 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)