The Moors arrived in Spain as a conquering force in the 8th Century, took over nearly all of the Iberian Peninsula, and ruled it, to a greater or lesser extent, for nearly eight centuries.

The Visigothic hold on the Iberian peninsula was waning as the 8th Century began. Toledo, the capital, was hemorrhaging control because of a dread combination of famine, disease, and internal dissent. In 711, a rival claimant to the throne of King Roderic appealed for assistance to the Arabs and Berbers who lived in North Africa, just across the Straits of Gibraltar. By then converted to Islam, the Moors, as they came to be known, were only too happy to oblige and arrived with a 10,000-soldier-strong army. That army made quick work of Roderic and the Visigoths at the Battle of Guadalete, and the invaders set about rolling up opposition further north. It took them only seven years to conquer all but a bit of Asturias.

The Moors renamed the place al-Andalus. In 718, the remnants of the European presence began a centuries-long struggle to retake Spain. This was the Reconquista.

This struggle to oust Muslim armies from ruling Spain began in 722, with a small victory by the Asturian Don Pelayo. Asturias quietly annexed its western neighbor, Galicia, in 741. The result was a Christian land that later became the Kingdom of Leon.

Meanwhile, a confident Moorish army crossed the Pyrenees into what is now France, marching ever northward toward the English Channel. They were stopped monumentally by Charles Martel and a Frankish army at the Battle of Tours, in 732. The invaders turned back south.

One of Charlemagne's few failures was an expedition against Muslims armies in what is now Spain in 778. Frankish armies seized the town of Pamplona but could not take Saragossa and so decided to abandon the expedition. During this campaign, the Franks fought in the Battle of Roncevaux Pass, a disaster for the Franks that resulted in the death of the count Roland of the Breton March, whose story is told in the epic poem The Song of Roland. Charlemagne came back some years later, took what is now Barcelona, defeated the Saracens, and established a buffer known as the Spanish March.

In the mid-750s, a member of the Muslim world's ruling Umayyad family, Abd-al-Rahman, struck out on his own, leaving Syria for the perimeter of the Iberian and establishing an independent emirate in Córdoba. He and his descendants ruled over most of what is now Spain and Portugal for more than a century.

At a time when many European cities had gone "dark," Muslim cities were lighting the way to the expansion of knowledge and technology. Astronomy, math, and medicine all flourished in Córdoba and other such cities. The capital boasted a thriving university, and one of the largest libraries in the world, courtesy of Al-Hakam II. Libraries and bookshops were popular throughout Al-Andalus, as was the use of paper, not only in books but also in bills of sale and notices.

Moor rulers also introduced new crops into their part of the peninsula. Almonds, artichokes, bananas, dates, figs, lemons, oranges, peaches, rice, saffron, and sugar all found new homes, the crops all irrigated using new techniques imported from the Middle East. As well, cities were vibrant collections of neighborhoods of houses connected by paved streets lit by street lamps–a scenario much more advanced than elsewhere in Europe.

Moorish armies reconquered Barcelona in 985 but lost it again not two decades later. By that time, the dominant overlord had become a collection of squabbling lords.

One land that had held out against nearly all comers was the home of the Basques. That land rose to prominence in the 10th Century as the Kingdom of Navarre. Several years later, the Navarre leader Sancho the Great aligned himself with the Kingdom of Castile and conquered nearly all of Leon. His death resulted in a division of his lands, and the next warrior to conquer Leon, Ferdinand I of Castile, took his land to preeminence. During the next two centuries were born the peninsula's four leading Christian kingdoms: Aragon-Catalonia, Castile-Leon, Navarre, and Portugal (independent in 1143).

The Almoravids were the ruling Muslim dynasty in the 11th Century. At the same time, in the East, Christian armies were marching and sailing to retake the Holy Land in the Crusades. The fervor of Reconquest burned within thousands of Christian warriors. Alfonso VI of Castile took back Toledo in 1085, gave it back the very next year, and kept up the struggle. A decade later, Alfonso found his most loyal supporter in Rodrigo de Bivar, who came to be known as El Cid, led his army in the takeover of Valencia (which they held until his death, in 1099). Zaragosa fell to Christian armies two decades later.

Into this fray stepped the Almohads, a dynasty of Berbers whose ancestors were the original Muslim invaders of Hispania. An Almohad force took Seville and Marrakesh in 1147. In that same year, an army of English and German knights on the way to the Second Crusade helped Afonso Henriques capture the city of Lisbon and ensured that King Afonso I could rule over all of Portugal.

During the last half of the 12th Century and for much of the 13th Century, the Christian kingdoms worked more and more together. In 1212, Aragon, Castile, Navarre, and Portugal combined to defeat a Muslim force at Las Navas de Tolosa. Christian armies took Córdoba in 1236, Valencia in 1238, and Seville in 1248.

By this time, only the southern tip of the peninsula remained in Muslim hands. The Sierra Nevada protected the Kingdom of Granada from further Christian penetration. Muhammad I, in 1232, was the first King of Granada, and he made a client agreement with Castile that kept the peace so long as money from Granada kept filling Castilian coffers.

The various Spanish kingdoms consolidated themselves and looked without for several decades before the idea of Reconquista flowered again. Navarre got involved in various intrigues in France (at times being subject to the king of that country), as did Castile, a onetime ally of the Continental defenders in the Hundred Years War. Aragon looked to expand its influence in the Mediterranean, getting involved in a number of conflicts, political and military, in Italy; by the 15th Century, Aragon could claim ownership of the Kingdoms of Naples, Sardinia, and Sicily.

It was a combination of Aragon and Castile power that brought about the final conquest of Granada, in 1492. That combination came by way of the marriage of Ferdinand of Aragon and Isabella of Castile, in 1469; her ascension as Queen of Castile, in 1474; and his ascension as King of Aragon, in 1479. The combination of those kingdoms' armies brought about the final will and might needed to take Granada. The Reconquista was complete.