Britain's most famous landmarks including the London Eye, Houses of Parliament, Downing Street and Gateshead's Millennium Bridge were plunged into darkness for an hour last night to mark the moment Britain first declared war on Germany in 1914.
It's an breath-taking image that commemorates those who died in the Great War - thousands of ceramic poppies surround the Tower of London, where a hundred years ago, some of the first volunteers enlisted.
Eventually there will be one poppy for each serviceman from Britain and the Colonies who died - creating a stunning 'field'of nearly 900 thousand 'blooms'. Today even the Royals were captivated by the display, as Royal correspondent Tim Ewart reports:
As the Lights Out event to remember those who fought and died in WWI happened last night ITV asked our viewers what they did to take part.
Lights on some of Britain's most famous landmarks were extinguished between 10pm and 11pm to remember those who died in WWI.