FOLKESTONE, UNITED KINGDOM - AUGUST 04: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Prince Harry unveils a plaque as he attends the 'Step Short' commemorative event to open the Folkestone Memorial Arch, to mark the centenary of the First World War on August 4, 2014 in Folkestone, England. 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 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 causalities. A series of events commemorating the 100th anniversary are taking place throughout the day. (Photo by Max Mumby/Indigo/Getty Images)