In 1478, the Spanish Inquisition was formally established by Ferdinand II of Aragon and Isabella I of Castile. The institution was created to ensure religious orthodoxy within their kingdoms, functioning as a powerful mechanism for state-sanctioned control and investigation.

The primary focus of the Inquisition was the examination of converts, particularly those of Jewish or Muslim heritage who were suspected of secretly practising their former faiths. This process of scrutiny sought to enforce religious conformity across Spain and its expanding empire.

The institution became notorious for its methods of surveillance, censorship, and the administration of severe punishments. Its influence extended far beyond simple religious inquiry, shaping the social and political landscape of the Iberian Peninsula for centuries.

Key aspects of the Inquisition included:

• The pursuit of religious uniformity under the Catholic Monarchs.
• The investigation of suspected apostasy among recent converts.
• The implementation of strict censorship to control public discourse.
• The use of judicial processes to enforce institutional authority.
• The expansion of its influence throughout the Spanish Empire.