On the landing of her home, Rosalind Grey has a large, fading photograph of a man she never knew.
"I think of him often," she said. "Every time I pass the photograph, I think what a terrible tragedy and waste that I never knew my grandfather and what a greater tragedy that my father was left with no memory of his own father."
The name of the man in the photograph is Walter Lockwood. He was killed, aged just 28, in the Battle of the Somme on 24 August 1916, leaving a widow and six young children. His body was never found.
Today, Ms Grey, 60, from Ely in Cambridgeshire, will be one of more than 100 relatives of soldiers who died on the Somme, boarding a special Eurostar train at Waterloo station to travel to the battlefield in northern France. They will take part in an event that will make history, not the history of the war but the history of how we remember the war.
The Duke of Kent will open an educational visitor centre, the first of its kind to be built on any British battlefield of the First World War. It is an Anglo-French project, paid for two-thirds by French taxpayers and the European Union and a third by private British donors, including Rosalind Grey.
Although there are several private museums on the battlefields, French and Belgian museums and visitor centres for Commonwealth countries, there has, until now, been nowhere to tell the story of the British role in the most terrible battles in history.
How was the war fought? What were the Pals battalions. Why were the British in France at all? Why were more than a million British, French and Germans killed in the five months of the Somme alone?
The £1.8m centre in the village of Thiepval, close to the great Portland stone and brick arch designed by Sir Edwin Lutyens, is dedicated to the 72,000 British "Missing of the Somme".
Those on the Eurostar train today - partly paid for by Eurostar - will include earls Haig and Kitchener, the sons of the two leading British military figures in the Great War; members of the Lutyens family; and the author Sebastian Faulks, whose novel Birdsong has helped generate interest in the war in younger Britons.
The centre, sunk into the ground to preserve the sight lines of the Lutyens memorial, contains hi-tech equipment and displays to explain the battle from the British, French and German viewpoints. The aim is to be factual, enlightening and moving - not jingoistic or simplistically anti-war.
The opening marks the end of a six-year campaign by a small group, led by Sir Frank Sanderson a retired businessman from Sussex. The Somme centre was resisted by traditionalists, including some senior officials in the Ministry of Defence. They believed the 1914-18 battlefields and cemeteries should be left to speak for themselves.
Sir Frank Sanderson maintained that information was necessary, certainly for the young. More Britons are visiting the battlefields than ever before but the memory is fading as the last few centenarian survivors die.
Sir Frank and his team persuaded the local council, the French government and the European Union to back the scheme. After appeals in The Independent and The Daily Telegraph, Sir Frank raised £600,000.
Ms Grey said: "Every time I go, I have a strange feeling that somewhere out there, there is a flower or blade of grass which owes its life and strength to my grandfather's body."