Lights have gone out across the capital to mark the centenary of Britain's entry into the First World War.
London landmarks including Tower Bridge, the London Eye and Downing Street went dark to commemorate the moment.
The screens of Piccadilly Circus played a roll of honour naming the 2,000 residents of Westminster borough who fought and died in the war.
— DCMS (@DCMS) August 4, 2014
— NPAS South East Region (@NPASSouthEast) August 4, 2014
The work of art "Spectra" created by Japanese artist Ryoji Ikeda shone a white column of light into the sky which could be seen across the city.