Research Guide
The French Pyramid: Régions, Départements and Communes Explained for Genealogists
Every American researcher who opens a French record hits the same wall, and it isn't the language. It's the geography. The record says your ancestor was born in a place you've never heard of, "canton de X, arrondissement de Y", and none of it maps onto the state-county-city logic you grew up with. France organizes itself as a pyramid, several floors deep, and your ancestor's records live at the very bottom of it. Learn the pyramid once and every French document you ever open will suddenly make sense.
The pyramid, floor by floor
The commune: where your ancestors actually live (on paper)
Here is the fact that changes everything: since 1792, every French birth, marriage and death has been recorded by the mairie of a commune, and France has about 35,000 of them. A commune can be Paris, with two million inhabitants, or a hilltop village of forty souls. Both have a mayor, a town hall, and registers. There is no "unincorporated" France: every square meter of the country belongs to exactly one commune, and every person who ever lived there left their paper trail in that commune's books.
One trap hides inside this beautiful system. Family stories often name a place that is smaller than a commune: a hamlet, a farm, a mill, what the French call a lieu-dit. Those places kept no registers of their own. If your family "came from La Roche", the real question is which commune the hamlet of La Roche belongs to, and that is what a good map (Géoportail, or the old Cassini maps) will tell you.
The département: where the records are kept today
The Revolution invented the départements in 1790, drew their borders so that anyone could reach the capital town in a day's ride, and named them after rivers and mountains: Vienne, Dordogne, Bas-Rhin. Old communal registers were later deposited with each département's archives, and it is these archives départementales that digitized them and put them online for free. In practice, French genealogy means identifying the commune, then working in the website of its département. Our guide to the free French archives walks through exactly how.
The floor below the pyramid: parishes and provinces
The pyramid above describes France since the Revolution. Climb past 1792 in your research and the vocabulary changes underneath you. Before civil registration existed, records were kept by the Church: the unit was the paroisse (parish), and the registers record baptisms, marriages and burials rather than births and deaths. Most parishes became communes in 1792, so the continuity is usually smooth, but not always: parishes merged, split, or shared a priest, and a large commune could contain several parishes.
And before the départements, France was divided into historic provinces: Normandie, Bretagne, Poitou, Alsace, Provence. This is the layer your family's memory probably speaks. An American family says "we came from Normandy"; the archives answer in départements, and Normandy alone covers five of them (Calvados, Manche, Orne, Eure, Seine-Maritime). Translating the family legend from province to département to commune is, in miniature, the whole job of early French research.
What you can safely ignore
Good news: most of the pyramid's middle floors barely matter for genealogy. Régions hold no records. Arrondissements and cantons are context you'll read past in most documents. The two exceptions worth remembering: the big three cities (Paris, Lyon, Marseille) file their civil records by municipal arrondissement, so "born in Paris" immediately raises the question "which arrondissement?"; and military conscription registers are organized by recruitment bureau, which follows cantons. Everything else in French research comes down to two levels: the commune where the record was written, and the département whose archives hold it now.
The pyramid in one sentence
When the family legend says a province, look for the départements it became; when the record names a hamlet, find its commune; when you have the commune, open its département's archives. That sentence is the compass. Everything else is reading old handwriting.
Lost somewhere in the pyramid?
I'm a French native based in the United States, and this system is the one I grew up in. Right now, before my professional launch, I'm researching a small number of families completely free of charge.
Join the Founding Families listFrançois is a French-born genealogist living in the United States. New to French research? Start with the New to French research? Start with the complete guide to tracing your French ancestry. Continue with parish or commune, and the 1792 line that decides where your record is · how to find the French village your ancestor came from or the free French archives online. Looking for a recent generation? Read how to find your French grandparents. Louisiana or Maritime roots? Read Cajun and Acadian roots back to France. And for the one corner of France whose commune belonged to two countries in turn, read was your ancestor French or German.