Huguenots may have been a tenth of France by 1572
Huguenots were French Protestants of the Reformed, Calvinist tradition, concentrated in the south and west. Hans Hillerbrand estimates their share reached as high as ten percent of the realm just before the 1572 St. Bartholomew killings. How the nickname arose is still argued.
Calvin’s teaching won over large parts of the nobility and town bourgeoisie, and between 1560 and 1570 Protestants grew to around 1.8 million people worshipping in some 1,400 Reformed churches. Whole districts around the Massif Central and the Dordogne turned Reformed, though in many regions ordinary villagers stayed Catholic. Rising Catholic hostility led to the Wars of Religion, fought on and off from 1562 to 1598, with Jeanne d’Albret, her son the future Henry IV and the princes of Condé leading the Protestant side.
The Edict of Nantes in 1598 granted broad religious, political and military autonomy. Rebellions in the 1620s stripped the political and military part, and Louis XIV squeezed the rest, billeting dragoons on Protestant households to force conversions before the Edict of Fontainebleau in 1685 abolished legal recognition. Their share fell from 7–8 percent around 1600 to about 1 percent by 1686. Louis boasted that 800,000 or more adherents had shrunk to barely a thousand, an exaggeration, yet the exodus drained France of skilled and prominent people.
Persecution continued under Louis XV until Calvinism had almost vanished by 1774. Louis XVI’s Edict of Versailles ended it officially in 1787, and the 1789 Declaration of the Rights of Man made Protestants equal citizens. The Reformed Church of France carried the tradition on until a 2013 merger with Lutherans created the United Protestant Church of France, now the country’s largest Protestant body; the Huguenot cross remains its emblem.
The name began as an insult of uncertain origin. One theory links it to Besançon Hugues, a Catholic leader of Geneva’s anti-Savoy Confederate Party. O. I. A. Roche preferred a Dutch-German blend of words for secret housemates and oath-bound comrades, while Janet Gray insists a word so widespread must be French, and another tale ties it to a night-roaming ghost of Tours, King Huguet.
Source: Huguenots