Rome Publishes the Index of Forbidden Books
The Roman Inquisition tries to keep Protestant ideas out of Catholic hands by banning the books that carry them
Quick facts
- Issued by
- Sacred Congregation of the Roman Inquisition, under Pope Paul IV
- First edition
- 1559
- In force until
- 1966
What happened
The Sacred Congregation of the Roman Inquisition, under Pope Paul IV, issued the first Index Librorum Prohibitorum in 1559, a list of more than a thousand banned titles and authors divided into categories: writers whose entire output was forbidden, individual condemned books, and anonymous forbidden works. The Index explicitly named the movement's founders, stating that the books of heresiarchs such as Luther and Zwingli were absolutely forbidden. Its stated purpose was to stop the spread of heresy by preventing ordinary Catholics from reading, or even hearing read aloud, any work the Church had not expressly approved. The Council of Trent later revised the Index and it was ratified again in 1564.
Why it matters
The Index formalized the Catholic Church's use of centralized censorship as a Counter-Reformation weapon, extending well beyond theology into philosophy and science over the following centuries. It remained in force, in revised forms, until 1966, making it one of the longest-running official censorship systems in European history.
How we know
The Index itself survives as an official published Church document, reissued and revised across four centuries; the World History Encyclopedia's article quotes the Index's own decrees naming specific reformers as banned authors.
Sources
- World History Encyclopedia. Index of Prohibited Books · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- World History Encyclopedia. Index of Prohibited Books · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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