A tribute to the millions who died in World War One.

Britain's iconic Houses of Parliament were plunged into darkness on Monday night.

All around the UK, at landmarks, in offices and homes, lights were turned off for an hour until 11pm, the time Britain declared war on Germany in 1914.

The conflict, which ended in 1918 became known as the Great War and claimed the lives of 17 million soldiers and civilians.

This "lights out" event was inspired by the words of wartime Foreign Secretary Sir Edward Grey, who said on the eve of the war: "The lamps are going out all over Europe; we shall not see them lit again in our lifetime."

Outside Downing Street, official residence of the British Prime Minister, a single lantern flickered.

The Duchess of Cornwall, wife of Prince Charles, joined senior politicians for a commemoration service at Westminster Abbey.

There, candles were extinguished one by one until only a burning oil lamp remained at the Grave of