Which major event marked the completion of the Reconquista in Spain?

The fall of Granada in 1492 marked the completion of the Reconquista, a significant historical milestone for Spain. The Reconquista was a centuries-long effort by Christian kingdoms to reclaim the Iberian Peninsula from Muslim rule, which began in the early 8th century. Granada was the last Muslim stronghold on the peninsula, and its surrender signified the end of Islamic political authority in the region.

Fernando and Isabella, the Catholic Monarchs, played a crucial role in this event, and their conquest of Granada solidified their power and the unification of Spain under Christian rule. Following the fall of Granada, Ferdinand and Isabella also initiated the Spanish Inquisition, which aimed to maintain Catholic orthodoxy in their newly unified kingdom, but the fall of Granada itself is the pivotal moment when the Reconquista was officially completed.

The other options represent significant events but do not denote the conclusion of the Reconquista. The marriage of Ferdinand and Isabella was crucial for the political consolidation of Spain but occurred before the Reconquista's end. The Spanish Inquisition was a direct aftermath of the Reconquista's completion, and the Treaty of Tordesillas dealt with the division of newly discovered lands, which occurred later in the context of the Age of Exploration.