The long, intermittent expansion of Christian kingdoms across the Iberian Peninsula at the expense of Muslim-ruled al-Andalus, conventionally dated 711 to 1492 — a process whose unity as a single, continuous religious 'reconquest' is largely a later construction, since medieval Iberian rulers routinely crossed religious lines, allied with the other faith, and fought their co-religionists. It ended with the fall of Granada in 1492, the same year as the expulsion of Spain's Jews and the first voyage of Columbus.
The word 'Reconquista' was barely used during the centuries it supposedly describes. For most of those 770 years, Christian and Muslim rulers in Spain signed treaties, paid each other tribute, hired each other's soldiers, and made war on their own co-religionists as readily as on the other faith. El Cid, the great Christian hero, spent years fighting for a Muslim king. The idea that all of this was one long holy war to take Spain back for Christianity was assembled mostly afterward, by chroniclers, churchmen, and later nationalists who needed a usable past. The events were real. The story binding them together is, in large part, a story told later.