D Steven Ledingham

“In 1966, the Roman Catholic Church formally ended the largest censorship drive in the history of the world, formally known as the Index Librorum Prohibitorum (the Index of Forbidden Books). Formally launched in 1559 under Pope Paul IV, this four-century project was remarkably successful, even against non-Catholics. The Church was so powerful in Europe and America that many authors would avoid controversial topics, or modify their works according to the Church's dictates, in order to avoid condemnation by the Church. Authors who ignored the Church's dictates and were banned had trouble finding publishers. Even if they were published, their books were often hard or impossible to find because bookstores were under pressure not to stock them.”
― Craig A. James, The Religion Virus: Why We Believe in God: An Evolutionist Explains Religion's Incredible Hold on Humanity