Everybody knows about the Crusades and how the Franks first won, then lost, the Holy Land from 1099 to 1291. But many people don't realize that at the same time, Christians in the Iberian Peninsula were successfully retaking it from the Muslims, who had held it since the eighth century, in the Reconquista.
The Iberian Peninsula contains Spain and Portugal on the west coast. Inside Spain are the old Christian kingdoms of Catalonia and Aragon in the northeast, Castille and Léon in the center, Navarre and Asturias on the northern border and Galicia in the northwest above Portugal. Spain also contains the old Muslim kingdoms of Granada on the southern coast, and Murcia and Valencia on the southeastern coast. Iberia has been deeply affected by its medieval history of religious conflict and alliance.
At the end of the Roman Empire, the Visigoth tribe took control of the Iberian peninsula. The capital of the Roman Empire in Iberia was Tarragona, a city on the eastern coast of Catalonia and south of Barcelona. The Visigoths were Arian Christians who did not believe in the Trinity. From the fourth century onward, the Church condemned the followers of this view as heretics who deserved whatever they got.
But the real reason why no one came to help when the Muslims invaded in 711 was because there was no help to spare. Western Europe had broken into a bunch of smaller entities. The former Roman Empire in the west was being harried by the Vikings in the north and Muslim pirates and armies to the south. The Eastern Roman Empire (Byzantium) in Constantinople on the Black Sea was still powerful in the east, but too far away to help the west.
The Muslims quickly took over Iberia. By 718, they had consolidated their control over the peninsula, leaving only a few small Christian kingdoms like Asturias and Pamplona (later, Navarre) in the north. They even raided deep into what is now France, reaching as far as Tours before they were knocked back.
They then established the caliphate of Al-Andalus with its capital in Cordoba. While the northern Christian kingdoms clung to life in the Pyrenees, most of the population in the south converted to Islam and all seemed well, at least in Muslim Iberia. The ninth and tenth centuries in Spain were a golden age of poetry, music, history, astronomy, literature, architecture and centralized, peaceful government.
Naturally, it couldn't last.
