The Reconquista is a period in the history of the Iberian Peninsula spanning from the early 8th century to the end of the 15th century.
The period refers to the efforts led by the Christian principalities and kingdoms in northern Iberia to counter the advance of the Moors and reclaim the lands occupied by the Moors in southern Iberia.
The Battle of Covadonga is considered the beginning of the Reconquista period. This battle took place in the Asturian region of northern Iberia. A Visigoth nobleman, Pelagius, rebelled against the Moorish rule. A sizable Moorish army was sent to counter him but he was able to rout the army with a handful of followers in the valley of Covadonga in 722.
This marked the earliest instance of a successful counter to Moorish advance. The decisive victory led to the establishment of the Kingdom of Asturias which was the first independent Christian principality in northern Iberia following the Moorish conquest.
The second major blow to the invading efforts of the Moors came when they attempted to advance into northeast Iberia. Here they were confronted by a sizable Frankish army led by Charles Martel. Martel was able to rout the Moorish army at the 732 Battle of Poitiers (Tours). This crushing defeat permanently marked the extent of the Moorish advance into northeast Iberia.
Barcelona was one of the most important cities near the Pyrenees to have fallen to the hands of the Moors. The Franks targeted the city in a prolonged siege from 799 to 801 and finally gained back control of the city. The Frankish control of Barcelona meant that the Moorish control was beginning to recede this side of the Pyrenees as well.
Asturias existed as a border principality to the northwest of Iberia from the early 8th century. To this were added a number of other Christian vassal states established by Charlemagne in the northeast in order to permanently block any potential Moorish advance towards the Pyrenees. These border principalities included the counties of Aragorn and Navarre which were to become independent kingdoms in time.
The Reconquista gained a definite shape and a unified direction in the 10th century when powerful Christian kingdoms began to emerge in the north of Iberia. Although these kingdoms often acted at the expense of each other, they took Moors as their common foes and their common military goal was to push southwards and annex as much Moorish territory as possible.
The Kingdom of Navarre came into being in the 9th century, the Kingdom of Leon came into being in the 10th century and the Kingdoms of Aragorn and Castile came into being in the 11th century. The Kingdom of Portugal came into being in the northeast of Iberia in the 12th century.
The Cordoba Caliphate, which was the unifying central authority of Moorish rule in Iberia, collapsed in the 11th century. This led to a period of civil warfare in the Moorish regions which led to the loss of many territories to the Christian neighbours.
By the 15th century, all Moorish territories save the Emirate of Granada had been lost. Granada was seized by the Kingdom of Spain in 1492 which effectively marked the completion of the Reconquista campaign.