First World War Centenary: Powerful images that capture the moment cheering Europe heralded the declaration of war

Photos make stark contrast with those from bloody battlefields in years that followed

These images show the crowds outside Buckingham Palace and Berlin Cathedral in August 1914 as war was declared (Rex Features)

It seems extraordinary now to think that people could celebrate the start of a terrible conflict that led to the deaths of 16 million people.

But these black-and-white images show the mirrored scenes of jubilation outside Buckingham Palace and Berlin Cathedral as it was announced 100 years ago today that Europe was to go to war.

In London, the 11pm deadline signalling Germany’s invasion of Belgium – and Britain’s declaration of war – came and went with cheering and singing on crowded streets.

Writing in his diary, the future Prime Minister Winston Churchill describes how “along the Mall from the direction of the Palace the sound of an immense concourse singing ‘God save the King’ flouted in”.

The German public was similarly in favour of an armed conflict, despite the apparent reservations of Kaiser Wilhelm II as he ordered the invasion of France “with heavy heart”.

London crowds cheering the Royal Family on the Buckingham Palace balcony on the day Britain declared war on Germany and Austria-Hungary, 4 August 1914 (Rex) (Rex Features)

The photographs of crowds cheering and decorous hat-waving come in stark contrast to the later scenes of muddy fields strewn with bodies with which we are now so familiar.

Marking the centenary of the start of the First World War today, the Prime Minister said it was an episode in history which had “profoundly changed our world”.

David Cameron paid tribute to those who lost their lives and speaking, outside Glasgow Cathedral ahead of a commemoration service, said it was important to find new ways of bringing the experiences of those involved in the conflict to life.

Crowds in Germany cheer the declaration of the First World War in front of Berlin Cathedral (Rex) (Rex Features)

“It is right to remember the extraordinary sacrifice of a generation and we are all indebted to them because their most enduring legacy is our liberty,” Mr Cameron said.

Within weeks of Britain declaring war on Germany, the two nations' forces clashed outside Mons, Belgium, leading to some 1,600 British casualties and 2,000 German.

This evening there will be a commemoration service at the St Symphorien Military Cemetery in Mons, while more than 650 events were scheduled to mark the day across the UK.

Everyone in the country has also been invited to take part in the Lights Out project, leaving just a single light on or candle burning for an hour from 10pm tonight as a reflection of the famous Sir Edward Grey quotation on the eve of the war: “The lamps are going out all over Europe, we shall not see them lit again in our lifetime.”

A candlelit vigil of prayer, readings and music will be held in Westminster Abbey this evening and separate events are scheduled in Canterbury and other cathedrals and churches.

Organisers have hailed Lights Out it as “one of the most dramatic UK-wide events ever organised”, where people will join a “shared moment of reflection” to commemorate the start of one of the darkest periods in our history.