Andrew Robertshaw, head of education at the National Army Museum, explains why there is still so much interest in a battle that is passing out of living memory.
The modern fascination with the Battle of the Somme has its roots in the casualties of both the first day and following months.
These were unprecedented in British military history. The British lost more than 19,000 men in the first day of battle; there were more than 420,000 British and commonwealth casualties by the end of the campaign in November.
For our European allies these casualties were almost to be expected.
More than 100 years earlier the French and Russians lost 77,000 men in the Napoleonic Wars at the Battle of Borodino in 1812. And the French army had lost nearly one million men between the outbreak of the Great War in August 1914 and Christmas 1915.
In 1914 Britain fielded an army smaller than Belgium's, but in 1916 it had produced its first mass citizen army consisting of the pre-war Regulars, Reservists and Territorials who had been joined by the Volunteers of 1914 and 1915.
This new volunteer army was drawn from all social classes and parts of the country. 'Pals' battalions swelled the British Expeditionary Force (BEF) to more than one million men.
The British population at the time was 46 million, therefore the number of men serving in the forces meant that few families did not have a relative serving at the front.
If war service touched nearly every family, then so did the casualties.
Families all over Britain and later the Dominions and Empire received the tragic news by letter or telegram, that a relative had been killed, was wounded or, typically for the conditions of the Battle of the Somme was missing.
The combination of bereaved families, the disabled who returned home and the veterans who rarely discussed their experiences have produced a legacy of family stories about the Somme. These have been passed down to a modern generation for whom the battle is history, but by family involvement, is also their history.
Many of those standing at the monument to the missing at Thiepval on 1 July this year as they meet to commemorate the fallen of the Somme, will be there to remember great uncles, great grandfathers and more distant relatives - men they never met, whom they know about from faded black and white photographs or a few letters or official documents.
However distant the relationship, it is these men who join the past with the present, who are the crucial link to a defining point in British and world history.
There is no question that in ten years' time public interest in the events of the Somme will have grown further still.
Britain lost more than 19,000 men on the first day of battle
Critically, as the battle slips firmly out of living memory there may be a process of reassessment of the events of 1916. Some of the certainties of the "Lions led by donkeys" approach to Great War history which dominated public opinion from the early 1960s is being challenged by historians who are prepared to put the war and battle into context.
This revisionism is bound to be controversial, but the simple assumptions of armchair experts with the benefit of hindsight must be scrutinised if we are to be able to distinguish between mythology and historical reality.
History is about interpretation, not simply "facts", and the process of investigation will continue for as long as interest in the Battle of the Somme is sustained.
I once asked my grandfather, himself a World War One veteran, whether he thought it was just too simple to assume the Great War amounted to nothing but a "futile" waste of life.
He replied: "The generals did their job, we did ours. We won."
The same man wept on 3 September 1939 when the Great War became the First World War and another generation went to fight a "war to end all wars". The Great War did not end war any more than did the Second World War.
That failure is not something to blame on the men and women who did "their bit" in either conflict.
"The Battle of the Somme 1916: The Evidence" exhibition opens on 29 June at the National Army Museum, London.
There will be live coverage of the Somme commemorative march on BBC News 24 and the One O'Clock and Six O'Clock News throughout the week.