Task: Question Generation
Input (English): Passage: In 1545, Polin was on his way to fight against the English in the area of Boulogne. While in Marseilles in 1545, Polin was involved as a leader in the massacre of the Protestant Waldensians . Outside the Piedmont the Waldenses joined the local Protestant churches in Bohemia, France and Germany. After they came out of clandestinity and reports were made of sedition on their part, the French king, Francis I issued on 1 January 1545 the "Arrêt de Mérindol", and armed a crusade against the Waldensians of Provence. The leaders in the 1545 massacres were Jean Maynier d'Oppède, First President of the parlement of Provence, and Antoine Escalin des Aimars who was returning from the Italian Wars with 2,000 veterans, the Bandes de Piémont. Deaths ranged from hundreds to thousands, depending on the estimates, and several villages were devastated.
Output (English): What one event caused the massacre?