It is the internet site that contains dark family secrets, unspeakable truths and appalling injustice. The French log on to it in trepidation and in private.

Les Guillotinés offers the most complete online list yet established of the French Revolution’s victims and invites users to discover the answer to a terrible question: “Do you have an ancestor who was decapitated?” Hundreds of thousands of people have consulted the death base, created by Raymond Combes, a computer programmer and amateur genealogist.

Many more are likely to follow suit. According to one estimate, up to five million French people are descended from victims of La Révolution.

Take, for instance, Denis Sarazin-Charpentier, a 54-year-old civil servant from Boissy-Le-Châtel outside Paris. Like all his compatriots, he was taught as a child that the guillotine fell on evil aristocrats. Then he found out that Claude Louis Deligny, his own ancestor, had lost his head in 1794 when revolutionaries discovered a cache of coins stamped with the King’s head in the family grange.

“He was condemned for plotting against the Revolution, but he was just a poor farmer and there was no plot at all,” said Mr Sarazin-Charpentier. “He only wanted to keep his money safe.”

Mr Sarazin-Charpentier, an amateur historian, said that the site – les. guillotines.free.fr – showed “they didn’t just guillotine the nobility. There were farmers, peasants and commoners who were decapitated as well.” More than two centuries later the subject remains highly sensitive in a country that sees the Revolution as its political bedrock.

“Personally, I don’t mind talking about my ancestor who was guillotined but I know families descended from the aristocracy who still can’t bear to mention it.” He added that France had tried to ignore the Terror in order to preserve the reputation of its revolutionaries “because it was the Revolution that created our Republic and no one really wants to call all of that into question”.

However, Mr Combes’s work may force historians to reappraise the period. According to the official figure 17,500 people were guillotined between 1792 and 1795. But Mr Combes already has more than 18,000 names on his site, which is based on lists compiled for the bicentenary of the Revolution in 1989 and from documents sent in by users.

“A lot of those guillotined were never registered in official records,” he said. “I’m adding names all the time. But I don’t put anyone down unless they are accompanied by documentary evidence.”

Nor has he included the tens of thousands of people massacred as violence swept across France at the end of the ancien régime. “It was an important part of our history,” said Mr Combes, 50. “But I’m not sure all that violence really served a purpose.”

Slice of life

— The Halifax Gibbet and the Scottish Maiden, forerunners of the guillotine, were used in the British Isles from the 13th century

— The machine takes its name from Dr Joseph Guillotine, who pressed for a decapitation machine in France to make execution quicker and more humane

— Many doctors have suggested that beheaded victims could remain conscious for up to 30 seconds after the blade fell

— The blade weighed just over 40kg (88lbs) and dropped 2.3m on to the neck of the victim, at a speed of 7 metres/second

— The last man to be executed by guillotine in France was Hamida Djandoubi – who tortured and murdered his former girlfriend, Elizabeth Bousquet – on September 10, 1977

Sources: napoleonguide.com; Oxford History of the French Revolution; BMJ; Book of Firsts, Patrick Robertson

Times Recommends

• ‘Thousands of Tamils dying’ in Sri Lanka camp
• Jackson 'rebuilt his nose before he died'
• Tehran: militiamen attack protesters