Despite officially not existing, the French nobility continues to endure and often thrive in the 21st Century.
Nancy Mitford - who spent much of her life in Paris - joked in one of her books that French nobles were far more touchy about status than their English peers.
Invite a French duke to the embassy, and you had to know whether he was a) an ancien regime duke, b) a Restoration duke, c) a Napoleonic duke or d) a Papal duke.
Each knew the correct order of precedence at dinner and would be mightily offended if the ambassador got it wrong.
Mitford was writing in the 1950s and today such ultra-snobbery (if it ever really existed) is a distant memory.
But the French nobility - la noblesse - is still very much alive. In fact, in sheer numbers there may be more nobles today than there were before the Revolution.
"We reckon there are 4,000 families today that can call themselves noble. True, at the Revolution there were 12,000 families. But today families are much broader. So overall we reckon there are between 50- and 100,000 nobles in France today - roughly the same as in the 1780s."
So says a man who should know - Jacques de Crussel, the Duc d'Uzes.
"The point," he goes on, "is that though many aristocrats disappeared in the revolution, afterwards in the 19th Century there were five kings or emperors of France - each of whom created his own nobility. So we stocked up on numbers!"
The Duc d'Uzes is president of a little-known body called the Association for Mutual Help of the French Nobility (ANF).
According to the story, the ANF was founded in the 1930s after two French nobles realised that the porter who was carrying their luggage at a Paris station was one of their own. They resolved to create and manage a fund to help distressed nobility - a function the ANF carries on to this day.
Its other job is one of research and certification. Every year come more than 100 applications from nobles - or maybe "nobles" would be better - wanting proof of lineage. Most are authentic, so - after exhaustive checking in the ANF's large archives - they are approved.
But there are mistakes and frauds too - men and women who claim to be from the nobility but are not. These are remorselessly weeded out.
One of the most common misrepresentations is from people who think that because their name contains the so-called particule or "de", they are therefore noble.
"Not a bit of it," says the Duc d'Uzes. "It is quite possible to be noble without a particule just as many people with the particule are definitely not noble!"
Valery Giscard d'Estaing, Dominique de Villepin and Charles de Gaulle, please take note.
So who are these hundreds of thousands of French noblemen and women? How do they perceive themselves? Are they noticeably different from the rest of the French?
There is, of course, no quick answer. Some families have retained wealth and influence. They live in the better arrondissements of Paris and provide captains of industry and finance.
Examples include Axa's Henri de Castries (who is actually a count) and Michelin's Jean-Dominique Senard (also a count, but of the Papal variety).
But many others live discreet lives far from the capital, often in old mansions or chateaux whose upkeep is a burden.
A typical example are the de Vogues - neighbours of mine in the Berry region of central France.
The de Vogues trace their origins back to 12th-Century Ardeche, and this branch settled at the Chateau de Pezeau near Sancerre before the Revolution.
Today Albert de Vogue - in his 80s - lives alone there, looking out on the land that he spent his life farming. Children and grandchildren come at weekends.
"I extract no particular glory from my origins - nor do I see them as anything to be embarrassed about," he says. "But I do feel I have a duty to pass on the family's Berry heritage."
His children are proud of their forebears - some of whom achieved greatness in different ways. They are Catholics of an undemonstrative kind, and they say that certain values - kindness to others, open-heartedness - are important to them.
But they feel a million miles from the society life of Paris.
"When I was a boy I went to the local school, and I said my dad was a farmer - which was true. It was not till many years later that I felt comfortable saying I lived in a chateau," says Albert's son Hugues.
The family has a strong connection with local people. Albert was for 15 years mayor of the village, many of whose families once worked on the de Vogue estate.
But there is more. In the war, Albert's father Arnaud de Vogue was a leader of the Resistance. Hunted by the Germans, he was sheltered by local farmers - some of whom were tortured and deported.
"It is a debt toward the people here that our family has never forgotten," says Hugues.
Over two centuries, the French noblesse has had to perfect an odd social game. The country is a republic, one of whose founding moments was a revolution in which many of their ancestors were killed.
Today the noblesse has no legal existence. There is no monarchy to lend it justification. The very idea of a caste of lords offends against France's cultural zeitgeist.
As a result most people born to the old families have learned to be discreet.
"We definitely do not trumpet it about," says Raphaelle Pinon (from another Berry family the Pinon de Quincy). "But at the same time I think we have a perspective on life and family and history that is very different. And I think that people see that."
Listen here to Hugh Schofield's report for Broadcasting House on BBC Radio 4