The Index Librorum Prohibitorum (English: List of Prohibited Books) was a list of publications deemed heretical, anti-clerical or lascivious, and therefore banned by the Catholic Church. The 9th century witnessed the creation of what is considered to be the first index, called the Decretem Glasianum, but it was never officially authorized. Much later, a first version (the Pauline Index) was promulgated by Pope Paul IV in 1559, which Paul F. Grendler believed marked "the turning-point for the freedom of enquiry in the Catholic world", and which lasted less than a year, being then replaced by what was called the Tridentine Index (because it was authorized at the Council of Trent), which relaxed aspects of the Pauline Index that had been criticized and had prevented its acceptance.