Answer by taking a quote from the following article:

The French (French: Francais) are an ethnic group and nation who are identified with the country of France. This connection may be legal, historical, or cultural. Historically the French people's heritage is diverse, including populations of Gauls, Ligures, Latins, Franks, Iberians, Alamans and Norsemen. France has long been a patchwork of local customs and regional differences, and while most French people still speak the French language as their mother tongue, languages like Norman, Occitan, Catalan, Auvergnat, Corsican, Basque, French Flemish, Lorraine Franconian, Alsatian and Breton remain spoken in their respective regions.

In France, the conception of citizenship teeters between universalism and multiculturalism, especially in recent years. French citizenship has been defined for a long time by three factors: integration, individual adherence, and the primacy of the soil (jus soli). Political integration (which includes but is not limited to racial integration) is based on voluntary policies which aims at creating a common identity, and the interiorization by each individual of a common cultural and historic legacy. Since in France, the state preceded the nation, voluntary policies have taken an important place in the creation of this common cultural identity. On the other hand, the interiorization of a common legacy is a slow process, which B. Villalba compares to acculturation. According to him, "integration is therefore the result of a double will: the nation's will to create a common culture for all members of the nation, and the communities' will living in the nation to recognize the legitimacy of this common culture". Villalba warns against confusing recent processes of integration (related to the so-called "second generation immigrants", who are subject to discrimination), with older processes which have made modern France. Villalba thus shows that any democratic nation characterize itself by its project of transcending all forms of particular memberships (whether biological - or seen as such, ethnic, historic, economic, social, religious or cultural). The citizen thus emancipates himself from the particularisms of identity which characterize himself to attain a more "universal" dimension. He is a citizen, before being a member of a community or of a social class Therefore, according to Villalba, "a democratic nation is, by definition, multicultural as it gathers various populations, which differs by their regional origins (Auvergnats, Bretons, Corsicans or Lorrains...), their national origins (immigrant, son or grandson of an immigrant), or religious origins (Catholics, Protestants, Jews, Muslims, Agnostics or Atheists...)."

Were the French people into Multiculturalism?
the conception of citizenship teeters between universalism and multiculturalism,