There is a paradox from the First World War that is still with us. The war perfected military slaughter on an industrial scale. It also marked a new reverence for individual soldiers - for the fathers, sons, brothers, lovers who died in their millions.

The invention of ever more lethal weapons coupled with improved transport systems enabled large armies to fight not just for a day or a week, but for years – and they did. The century before also created parliamentary democracy – rudimentary human rights, psychoanalysis, and education for all. In Britain, France and Germany, even the identity of the poorest and most obscure individuals began to matter.

In no previous war had so many died nor was such an effort made to honour the ‘sacrifice’ of private soldiers. No previous war built memorials with the names of individual soldiers, let alone in every village and town in Britain and France. No previous war created battlefield cemeteries in which even the lowest ranks had an individual grave.

While there is a monument to mark the spot and major station in London named after it, the dead of the battle of Waterloo (1815) have no graves. Bodies in those days were dumped into large pits; later the bones were recovered and brought back to Britain, crushed and turned into fertilizer.

The slaughter in the 1914-18 war was so intense and the shells so powerful that hundreds of thousands of bodies were never found or identified. The failure to find a body - the fact that an individual could just be shredded into many pieces by the actions of constant shelling or drowned in mud - was not tolerable to official and popular opinion, even though mass slaughter was acceptable or, at least, accepted by most.

British and French governments dealt with the problem in different, ways. The French buried an ‘unknown soldier’ beneath a flame under the Arc de Triomphe, to represent the 350,000 French soldiers who disappeared without trace. Grieving parents, wives and sweethearts were encouraged to believe that the Soldat Inconnu represented their loved ones. The British on the other hand created enormous memorials to ‘the missing’ such as those at the Somme, Tyne Cot and Ypres.

Anthelme Mangin was a French soldier who returned from captivity in Germany in 1918 with no memory and no identity. He was put in a mental institution and his photograph published in newspapers. He was claimed as a lost brother or son or husband by scores of families, mostly in France but also as far away as Scotland and Canada.

For 20 years, Mangin became one of the best-known names and faces in France, his story told and retold. The legal and political battles to claim him by competing families (19 claims as late as 1934) became a symbol of France's vast grief for its 1,200,000 lost men. It symbolised the refusal of many to believe that their loved ones were lost.

All claims were finally rejected, and Mangin was legally identified in March 1939 as Octave Monjoin, a waiter from central France. By then, all members of his immediate family had died. Once his identity was known, interest collapsed. He was no longer the ‘living unknown soldier’ but just another crazy veteran of the war. He died in a mental institution in September 1942, probably a victim of the starvation imposed on patients by the Vichy regime, which claimed to be founded on traditional, Christian values.