Final answer:
The censorship of printed books and the issuance of an Index of prohibited books for Catholics was established by the Catholic Church under Pope Paul IV around 1557 as part of the Catholic counter-reformation efforts.
Step-by-step explanation:
The censorship of printed books and the creation of an index of books forbidden for Catholics, known as the Index Librorum Prohibitorum, was established by the Catholic Church. This was implemented to ensure that Catholic readers did not encounter heretical or otherwise damaging content that could lead them astray from church teachings. The Index, first initiated around 1557 under the authority of Pope Paul IV, was regularly updated by the Roman Congregation of the Index, a former dicastery of the Roman Curia. Its enforcement was part of the counter-reformation efforts to combat the influence of Protestant reformation and humanist thought which were being spread through printed material.
The establishment of the Index reflects a period where control over information and ideas was paramount for maintaining religious authority and doctrinal purity. This practice aligns with the broader context of historical censorship measures by various authorities, intended to regulate the public's exposure to certain ideas, whether for religious, moral, or political reasons.