France's religious wars killed between two and four million people
Between 1562 and 1598, French Catholics and Protestant Huguenots fought a string of civil wars that cost two to four million lives through violence, famine and disease. Peace came when Henry of Navarre, a Catholic convert since 1593, became Henry IV and issued the Edict of Nantes.
Friction between the faiths had been growing since the 1530s, feeding on regional rivalries and noble ambition. Everything accelerated when Henry II died by accident in July 1559. His widow, Catherine de' Medici, found herself competing for power with great families: the militantly Catholic Guise and Montmorency clans on one side, the Protestant House of Condé and Jeanne d'Albret, queen of Navarre, on the other. Foreign powers joined in, Spain and Savoy backing the Catholics while England and the Dutch Republic helped the Protestants.
A moderate camp, the Politiques, wanted order through a stronger crown and concessions to the Huguenots rather than the persecution practised by Francis I and Henry II. Catherine first sided with them, but her Edict of Saint-Germain in January 1562 enraged the Guise faction, and general fighting erupted by March. Historians agree the wars began with the killings at Wassy that year. Later Catherine turned harder and supported the St. Bartholomew's Day massacre of 1572, when Catholic crowds murdered somewhere between 5,000 and 30,000 Protestants across the kingdom.
One scheme by the American military historians Kiser, Drass and Brustein counts separate wars in 1562 to 1563, 1567 to 1568, 1568 to 1570, 1572 to 1573, 1575 to 1576, 1576 to 1577 and 1580, most of them fought in western and southwestern France; another common label is the Eight Wars of Religion. Truces kept collapsing into new rounds of fighting. The exact end is disputed too: some point to the Edict of Nantes on 13 April 1598 and the Peace of Vervins that May, others to the Peace of Alès in 1629.
The turmoil shook the last three Valois kings, all sons of Catherine: Francis II, Charles IX and finally Henry III. Henry IV, first of the Bourbons, answered with a centralised state and legal toleration, though many Catholics never accepted him, and his murder in 1610 sparked renewed Huguenot risings in the 1620s. The protections he granted lasted until his grandson Louis XIV revoked the Edict of Nantes in 1685.
Source: French Wars of Religion