When Did Spain Become Christian?
Spain was Christian from the late Roman period through the Visigothic kingdom until 711, and became Christian again through the centuries of the Reconquista.
Short answer
Spain was Christian from late antiquity, having been Christianized under Roman rule by the early fourth century. The Visigothic kingdom, which ruled most of the peninsula from the sixth century to 711, was a Catholic Christian state, and the Christianization of the peninsula was essentially complete by the end of the Roman period. In 711, the Arab-Berber conquest of most of the peninsula introduced a new Islamic political order, although substantial Christian populations continued to live under Muslim rule. The Christian reconquest of the peninsula, the Reconquista, began in the eighth century in the north and was completed in 1492, with the fall of Granada, the last Muslim state in Spain.
Christian Spain Under Rome
Spain was one of the earliest regions of the western Roman Empire to be Christianized. The Christian community of the peninsula dates at least to the third century, and perhaps earlier: the traditional chronology of the early Spanish church places the apostolic origins of Christianity in Spain with the mission of St. James the Greater, and the seven bishops of the Vitae Patrum Emeritensium were sent to Spain in the third century by Pope Fabian. The historical core of these traditions is that, by the time of Constantine, Christian communities existed in many of the major cities of Spain — Mérida, Seville, Tarragona, Zaragoza, Córdoba, León, Astorga, and others — and that the Edict of Milan of 313 freed the church to develop into a major social and political force.
The Roman Christian church in Spain produced, in the fourth century, the first great flowering of its institutional life. The Council of Elvira (c. 305), one of the earliest surviving church councils in the West, was attended by nineteen bishops from across the peninsula and issued eighty-one canons on the discipline of the clergy, the laity, and the sacraments. The Council of Arles (314), summoned by Constantine to settle the Donatist controversy, was attended by Spanish bishops and bound the Spanish church more closely to the wider Christian world. The subsequent fourth-century councils of Saragossa, Toledo, and Sirmium (in the Balkans) involved the Spanish bishops in the doctrinal controversies of the period, especially the Arian controversy. By the time of the Visigothic settlement in the fifth century, the church in Spain was a well-organized institution with a clear hierarchy, a body of canon law, and a substantial network of monasteries.
The Visigothic Catholic Kingdom
The Visigoths entered Spain in the early fifth century as a Germanic Arian Christian people, and for the next century and a half they ruled a Catholic population while remaining Arian themselves. The famous conversion of King Reccared I in 587, at the Third Council of Toledo, was the moment at which the ruling dynasty of the Visigothic kingdom became Catholic; the subsequent conciliar legislation made the profession of Arian Christianity a criminal offense and the practice of Catholic Christianity the public religion of the kingdom.
The Visigothic church of the seventh century, organized around the metropolitan sees of Toledo, Seville, Mérida, Tarragona, Narbonne, and Braga, was one of the most impressive in the early medieval west. The seventeen Councils of Toledo held between 589 and 702 produced a substantial body of conciliar legislation on doctrinal, liturgical, and disciplinary questions. The church was wealthy: bishops, drawn from the great landowning families, were often the largest single political force in their dioceses. The liturgy of the Spanish church, the so-called Mozarabic rite, was distinctive and influential. The monastic life, although less prominent than in some other parts of the early medieval west, was active in major centers like Compludo, Samos, and the great monastery of San Juan de la Peña in the Pyrenees.
The Christianization of the Visigothic kingdom was, by the late seventh century, essentially complete. The few surviving pagan or Jewish communities were small, urban, and politically marginal; the public religion of the kingdom was Catholic Christianity, and the church was the most powerful single institution in the realm. The Arab-Berber conquest of 711 was, in religious terms, a conquest of a Christian kingdom by a Muslim force; it did not represent the conversion of a pagan Spain to Christianity, and it did not represent the first Christianization of Spain.
The Muslim Conquest of 711
The Arab-Berber invasion of 711 was one of the most consequential events in European history. A small force of Berbers and Arabs, sent by the governor of Muslim North Africa, crossed the strait of Gibraltar and defeated the last Visigothic king, Roderic, at the Battle of Guadalete. Within five years, the entire peninsula south of the Cantabrian mountains had been incorporated into the Muslim state of al-Andalus. The Christian populations of the peninsula were subjected to Muslim rule under the so-called dhimmi regime, which protected them and their religion in exchange for the payment of a special tax (jizya). Christian communities continued to exist, especially in the northern mountain regions, in parts of Galicia, in the cities of the south, and in the Christian principalities of the Asturias and the Pyrenees.
The Christian principalities of the north, which became the political nuclei of the long reconquest of the peninsula, were established in the eighth century. The kingdom of Asturias, traditionally founded by Pelayo at the Battle of Covadonga in 722, was the most important. The county of Aragon, the county of Castile, the county of Barcelona, and the kingdom of Navarre emerged in the ninth and tenth centuries. The kingdoms of León and Castile, in the central and western zones, and the kingdom of Aragon, in the east, became the principal Christian states of the medieval period.
The Reconquista
The Christian reconquest of the peninsula was a long, slow process. It was not a single crusade, although the rhetoric of crusade was later applied to it; it was, in practice, a series of local wars, alliances, and population movements that gradually transferred the territory of al-Andalus to Christian rule. The principal stages were the consolidation of the Christian north in the eighth and ninth centuries; the repopulation of the Duero plateau in the ninth and tenth; the capture of Toledo in 1085 by King Alfonso VI of León and Castile; the foundation of Portugal as an independent kingdom in 1143; the great military orders of the twelfth century (the orders of Santiago, Calatrava, and Alcántara); the marriage of Ferdinand II of Aragon and Isabella I of Castile in 1469; and the final surrender of the Nasrid kingdom of Granada in 1492.
The fall of Granada on 2 January 1492 completed the political Christianization of the peninsula that the late Roman period had begun. The Catholic Monarchs, Ferdinand and Isabella, completed the Christianization of their realms by the expulsion of the Jews in the same year and the conquest and conversion of Granada, and the treatment of the Muslim population of Spain would become one of the central political and religious issues of the early modern period. The Christianization of medieval Spain was, however, a complex and gradual process that had been underway for over a thousand years before it reached its political conclusion.