In 1936, the Spanish military declared a coup against the (relatively) legitimate government of Spain, starting a civil war that would drag on for three long years. One of the principal points of contention was the role of the Catholic Church in the Spanish Republic; the military quickly gained support of Catholics, and territory they controlled was considered to be highly religious.
In the Republic-controlled territory, things were quite the opposite. The military's identification with the Catholic Church inflamed already-high tensions against the Catholic hierarchy and faith in the Republic; as a result, over the course of the war, over 7000 priests were murdered by angry citizens and militiamen. Bodies of Catholic priests and nuns were disinterred and displayed publicly. Churches were burned by the dozens, even hundreds. Angry militias broke into private homes, removed crucifixes and bibles, and burnt them. Thousands were killed for their faith by the time Fancisco Franco finally completed his overthrow of the Republican government in 1939. (Franco was guilty of his own set of wartime atrocities as well, including the bombing of civilian cities such as Guernica and the mistreatment and murder of hundreds of military prisoners.)
Think about this the next time you hear someone claim that liberals are trying to "outlaw religion" by asking that the Ten Commandments be removed from a public courthouse.