Edict of Fontainebleau
and outrage became the defining characteristic of the time, illustrated at its most intense in the St. Bartholomew's Day massacre of August 1572, when the Catholic Church annihilated between 30,000 and 100,000 Huguenots across France. The wars only concluded when Henry IV, a former Huguenot, issued the Edict of Nantes, promising official toleration of the Protestant minority but under highly restricted conditions. Catholicism remained the official state religion, and the fortunes of French Protestants gradually declined over the next century, culminating in Louis XIV's Edict of Fontainebleau—which revoked the Edict of Nantes and made Catholicism the sole legal religion of France. In response to the Edict of Fontainebleau, Frederick William of Brandenburg declared the Edict of Potsdam, giving free passage to French Huguenot refugees and tax-free status to them for 10 years.