Watch NASA Spacewalk Live
Aug. 4, 2014 marks the 100th anniversary of Great Britain declaring war on Germany, recognized today as one of the deadliest historical conflicts.
In 1914 British Prime Minister Herbert Asquith announced at 11 p.m. that Britain was to enter World War I after Germany violated Belgium neutrality. WWI, or the Great War, lasted until Nov. 11, 1918, and is recognized as one of the deadliest historical conflicts with millions of casualties. Monday, Aug. 4, 2014, marked the 100th anniversary of Great Britain declaring war on Germany.
In the photo above, a man looks upon the names of the dead prior to a candlelight vigil to mark the centenary of the WWI, at the National Memorial Arboretum on Aug. 4, 2014, in Stafford, England.
Schoolchildren look at names on the Roll of Honor during the Last Post Ceremony for Keith Heritage at the Australian War Memorial on the 100th Anniversary of the commencement of WWI in Canberra. Heritage was killed in action.
A British war veteran from the Chelsea Royal Hospital, shares a joke with a companion as they walk among WWI era cars in central London as part of a Great War Centenary Parade: a procession of more than 40 Edwardian cars to commemorate Britain's entry into the First World War.
Catherine, Duchess of Cambridge, Prince William, Duke of Cambridge, and Prime Minister David Cameron walk through war graves at St. Symphorien Military Cemetery in Mons, Belgium.
Britain's Prince Harry, Mons city mayor Nicolas Martin, Britain's Prince William and his wife Catherine, Duchess of Cambridge, appear on a balcony at the Mons townhall with Belgium's outgoing Prime Minister Elio Di Rupo.
Chelsea pensioners drive past parliament in an Edwardian era vehicle during the Great War Centenary Parade in London.
One hundred white crosses with names of some of those lost in the Great War stand on Parliament grounds to commemorate 100 years since the start of WWI, in Wellington.
Members of a living history group dressed as Gordon Highlanders march through a poppy-strewn field after a WWI centenary ceremony at the Bovington Tank Museum, in England.
Queen Elizabeth II attends a service of commemoration at Crathie Kirk Church in Aberdeenshire, Scotland.
Visitors attend a candlelight vigil to mark the centenary of the First World War, at the National Memorial Arboretum in Stafford, England..
Belgium's King Philippe, right, and Queen Mathilde stand with French President Francois Hollande as they wave on the balcony at the Liege city hall in Belgium.
Prince Harry attends the "Step Short" commemorative event to unveil the Folkestone Memorial Arch, marking the centenary of WWI in Folkestone, England.
British Major Maurice French, 84, of Heytesbury in Wiltshire, stands in front of his uncle's grave, during a commemoration ceremony at the St. Symphorien Cemetery in St. Symphorien, Belgium. Maurice Dease was the first person to receive the Victoria Cross in World War I. The cemetery was established by the German Army as a final resting place for British and German soldiers killed at the Battle of Mons. Among those buried is Pvt. John Parr of the Middlesex Regiment, the first British soldier to be killed in action on the Western Front.
A pillar showcased at a candlelight vigil marking the 100th anniversary of WWI, at the National Memorial Arboretum in Stafford, England.