On the second anniversary of the armistice following the end of the Great War of 1914-1918 the remains of a single Unknown Soldier were brought to London from the battlefields of the Western Front. Given the scale of the carnage and the fact so many of the fallen were simply unidentifiable, the idea to commemorate the dead through the remains of one anonymous soldier - that would represent them all - was more than just pragmatic. As an idea it had a symbolic, and poetic, resonance.
And so the remains of the Unknown Soldier were interred with full honours in Westminster Abbey in London. The outpouring of grief brought the United Kingdom to a standstill. There were extraordinary scenes as hundreds of thousands of people stood in respect on the streets of London as the body was returned home. Other Allied nations followed suit. Millions paid their respects.
But even from the beginning the concept of the Unknown Soldier was not without its critics - read by some as a figure of righteous anger, of the terrible mass anonymity of all those young men never identified, lost without trace. Moira looks at how the future of the Unknown Soldier as a timeless memorial is open to doubt for the simple reason that thanks to DNA testing, human remains are no longer unidentifiable. There is even a move to use DNA science to re-identify the remains of existing Unknowns around the world.
In this moving feature marking the centenary of Armistice Day, Moira asks whether the Unknown Soldier is finally an icon of war or peace, of sorrow and mourning - or is he a warning to us still?
Presenter: Moira Stewart
Producers: Jo Wheeler and Simon Hollis
A Brook Lapping Production for BBC World Service