The history of the Spanish Peninsula is closely bound to that of the Moors. The term "Spain" was not in wide use until the region was united by the monarchs of Aragon and Castile, and the Moors called the lands they ruled in the Iberian Peninsula Al-Andalus, traditionally thought to be an Arabic transliteration of Vandal, the Germanic tribe which briefly ruled the region in the early fifth century. The English name Andalusia derives from the Spanish Andalucia, which is still used by Spain to name its southern region.
Not surprisingly, three religions attempting to coexist during medieval times resulted in nearly incessant conflicts, marked by high taxation, disparate societies, rigid cultural controls, and systemic violence. Despite the odds, these three religions managed to live in a state of quasi-acceptance and peace in most of the major cities in the Iberian Peninsula like Cordoba and Toledo, with sporadic warfare occurring on the borders between Al-Andalus and the Christian kingdoms near the Pyrenees Mountains. Muslims, Christians, and Jews would attempt to reorganize their societies several times over the centuries through warfare, always with Jews on the lower rungs and Christians and Muslims fighting it out above them.
Though it's often forgotten today, the fighting that took place during the Reconquista was not originally driven by religion. Instead, the majority of the battles were fought by ambitious rulers who sought territorial expansion, like many other civilizations during the Middle Ages. In fact, the Reconquista would not gain its unique religious flavor until the 13th century, when the territories that would become Castile and Aragon drummed up religious fervor to achieve its aims and gained papal support from Rome.
While the Moors have always been associated with Spain due to their lengthy stay on the Iberian Peninsula, the most famous battle they were involved in was actually fought in modern France. While the Franks were consolidating a kingdom there, Muslim forces were pushing out of North Africa and into the Iberian Peninsula in the early 8th century, and by the dawn of the 730s, the Umayyad dynasty had expanded its territory from the Atlantic to the Pyrenees, a series of seasonally snow-capped mountains in Europe that forms a border between the nations of Spain and France. This would lead to Charles Martel's most famous military victory came at the Battle of Tours, also called the Battle of Poitiers, on October 10, 732.