The year 1492 may be most generally famous as the discovery of the New World by Christopher Columbus, but that date is also linked to this one. On January 2nd 1492, the Emirate of Granada surrendered to the forces of Ferdinand and Isabella of Spain.
This surrender marked the end of the Reconquista and Moorish rule of the Iberian Peninsula. The Reconquista, or "reconquest", was a period of history that lasted almost 800 years, starting with the Islamic conquest in 711-18 and ending with the fall of Granada, the last Islamic state.
This led to Spain's rise as a great power and was at least partly why they funded Columbus's fleet.
Image:Francisco Pradilla Ortiz [Public domain], via Wikimedia Commons (commons.wikimedia.org/wiki/File:La_Rendici%C3%B3n_de_Granada_-_Pradilla.jpg)