 In 1926, the passage of stringent anticlerical criminal laws and their enforcement by the so-called Calles Law, together with peasant revolts against land reform in the heavily-Catholic Bajio and the clampdown on popular religious celebrations such as fiestas, caused scattered guerrilla operations to coalesce into a serious armed revolt against the government.Both Catholic and anticlerical groups turned to terrorism.Of the several uprisings against the Mexican government in the 1920s, the Cristero War was the most devastating and had the most long-term effects.