From 1936 until the end of the Spanish Civil War members of various leftist groups wreaked terror across Spain in the name of social revolution.
Spanish political party divisions became increasingly embittered and questions of religious identity came to assume a major political significance. Electorally, the Church had identified itself with the Right, which had set itself against social reform.
The rebuttal set loose a violent onslaught on those that revolutionaries in the Republican zone identified as enemies. For several months afterwards merely to be identified as a priest, a religious or simply a militant Christian or member of some apostolic or pious organization, was enough for a person to be executed without trial.
The death toll of the Red Terror ranges from 38,000 to 110,000 people including 6,382 members of the catholic clergy.