The French Wars of Religion were a series of civil wars between French Catholics and Protestants (called Huguenots) from 1562 to 1598. Between two and four million people died from violence, famine or disease directly caused by the conflict, and it severely damaged the power of the French monarchy. One of its most notorious episodes was the St. Bartholomew's Day massacre in 1572. The fighting ended with a compromise in 1598, when Henry of Navarre, who converted to Catholicism in 1593, was proclaimed King Henry IV of France and issued the Edict of Nantes, which granted substantial rights and freedoms to the Huguenots. However, Catholics continued to disapprove of Protestants and of Henry, and his assassination in 1610 triggered a fresh round of Huguenot rebellions in the 1620s.
Tensions between the two religions had been building since the 1530s, exacerbating existing regional divisions, and quests for power among the nobles. The sudden accidental death of Henry II of France in July 1559 initiated a prolonged struggle for power between his widow Catherine de' Medici and powerful nobles. These included a fervently Catholic faction led by the Guise and Montmorency families, and Protestants headed by the House of Condé and the Navarrese queen, Jeanne d'Albret. Both sides received assistance from external powers, with Spain and Savoy supporting the Catholics, and England and the Dutch Republic backing the Protestants.