Thousands of 'walking ghosts' took to Britain's streets today to mark 100 years since the Battle of the Somme.
Each man represented a fallen soldier who died in one of the bloodiest battles in history in which more than one million men were injured or killed.
But the people behind the moving memorial were unknown - until now.
- Whose idea was it?
The idea came from Turner-prize winning artist Jeremy Deller who said: "I wanted to make a contemporary memorial to mark the centenary of the Battle of the Somme.
"One that moved the UK with unpredictability in which the participants, by their actions, took the memorial to the public."
The project was commissioned by the UK arts programme for the First World War 14-18 NOW, who were also behind the Tower of London poppy memorial.
- Who took part?
Around 1,400 men aged 16-52 - the age of those who would have been called up to fight - took part.
They were not trained actors but came from a range of professions - including a doctor, lawyer, shop assistant, GCSE student and sheep farmer.
They came together to rehearse in theatres around the UK for over a month before the performance.
It is one of the largest arts projects ever staged in Britain, with hundreds of additional volunteers working behind the scenes.
- What did they do?
Each participant represented an individual soldier who was killed on that day 100 years before.
Dressed in historically accurate uniforms, they handed out cards to members of the public with the name and regiment of the soldier they represented.
Appearing at various train stations, shopping centres and high streets around the country, the soldiers did not speak.
But at points throughout the day, they would sing the song "we're here because we're here" which was sung in the trenches in the First World War.
- How long did it take to put together?
The project took over a year to plan and volunteers worked for weeks under the strictest secrecy to ensure the performance was delivered in a powerful and unexpected way.
- What was the reaction to it?
Many Brits said they were moved to tears by the tribute which started the hashtag #WeAreHere.
From London Waterloo to Manchester Piccadilly, Glasgow to Plymouth, commuters stopped in their tracks at the moving sight of the actors.