US Edition But after decades of fending off the corrosive influence of Franglais and Hollywood, the efforts of L'Académie Française to preserve the purity of the French language now face a challenge from within France's own borders.
A parliamentary vote has led to more than 20 regional languages now being officially recognised by France's constitution for the first time in history, horrifying those who see France's single tongue as its unifying force.
The revolution has been brought about by lobbying from an unlikely alliance of minority groups, including Corsican nationalists, Breton druids, Germanic-leaning Alsatians, and even romantic poets from the southern Languedoc region.
Despite furious opposition from L'Académie, Article 75 of the revised constitution now states that all the languages "are part of France's heritage". As a result, French tax payers also face a multi-million Euro bill to make everything from road signs to menus into "regionally acceptable" dual-translation form.
Drivers will now have to head hanternoz, as well as nord, to reach the pretty Breton villages of the Cotes d'Armor, and when they sit down in a restaurant, they will order pesk as well as poisson.
Meanwhile, words like douar (Breton for earth), focu (Corsican for fire) hemmel (Alsatian for sky) and pechou (Franco-Provencal for small) could become as ubiquitous as 'le chewing gum' and 'le hold-up'.
Xavier North, who is in charge of the government's language policies, confirmed that a new parliamentary bill was planned for next year which would regulate the use of the newly acceptable regional languages in public services, transport systems, education, and the media.
'All will ensure that the regional languages share equal dignity with French,' he said.
It is a far cry from the founding principles of the French Republic, which has historically seen challenges to the one and only national language as tantamount to an attack on its very identity.
The Académie Française, which was set up in 1635, remains the official arbitor of French vocabulary and grammar.
It has led a rearguard action against what it calls the "Americanisation" of French life, ensuring huge subsidies for French film and fighting the encroachments of English in the world's of art and business.
Two years ago a French subsidiary of an American company was fined the equivalent of £400,000, with an ongoing fine of some £16,000 a day, for providing computer software to its employees in English only.
Per Vari Kerloc'h, the leader of the Gorsedd of Breton Druids, which champions Breton and Cornish culture, insisted the changes were fully compatible with the nation's distinguished past.
"Unlike today's members of the L'Académie Française, many great French writers admitted that regional languages and cultures were part of France's heritage," he said.
Critics of L'Académie have also accused its perpetual secretary, Hélène Carrère d'Encausse, of "misunderstanding, prejudice and Parisianism", for saying that regional languages had their roots in foreign tongues.
They have pointed out that less than a third of French people actually spoke French in the 19th century, while French government figures show that some 25 per cent of the population still have some knowledge of a regional language.
Almost 1.5 per cent of the population now speaks Alsatian, the heavily Germanic language favoured by many in the eastern Alsace region bordering Germany.
"How can putting street names in the regional language next to the French be divisive?" said Adrien Zeller, president of the regional council in Alsace. "What's divisive about using regional languages on regional television, with French subtitles - or vice versa?"