The Iberian Peninsula experienced two significant conversion movements in the Middle Ages: from Christianity to Islam after the Muslim conquest in the eighth century, and from Islam and Judaism to Christianity in the course of the long reconquest of the eleventh to fifteenth centuries. Neither Muslim conquest nor Christian reconquest had as an object the conversion or expulsion of infidels; rather, they aimed at the displacement of the vanquished ruling classes and the redirection of tax revenues to the conquerors’ fisc. That said, the success of the victors’ societies provoked conquered peoples to adopt the cultural and religious practices of the new regimes to the measure that these were seen to fill needs that their own cultures could not provide. Under Christian rule, official coercion, popular violence, and missionizing all failed ultimately to convert or integrate Jews and Muslims.
Scholarly opinion varies regarding the rate of conversion of Christians to Islam under Muslim rule, but the broad consensus is that the overwhelming bulk of the native population had converted by the late ninth century. Christians who adopted the cultural and linguistic manifestations of Islam but who retained their faith (known as Mozarabs) remained a significant minority into the twelfth century despite emigration to Christian lands. The descendants of converts (Arab. muwallads) often adopted the genealogy of Islamic patrons and were thus profoundly integrated into Andalusi society, although rebellions in the ninth century demonstrated that they maintained a distinct identity until that time. Jewish conversion to Islam was limited, but cultural assimilation was dramatic.
Under Christian rule, native Jews and Muslims (Mudé- jars) tended to be implicated in royal, ecclesiastical, and local economies (the former as financiers, the latter as producers and laborers) to such a degree that it was rarely in the interests of clerical or secular institutions to actively promote conversion. Nevertheless, the missionary ideal was publicly promoted, although subtle legal obstacles were often presented to would-be converts, who for their part found that adopting the Christian religion was no guarantee of social acceptance. In the thirteenth century, missionary work was undertaken by the Dominicans and Franciscans (including the lay brother Ramon Llull), who obliged non-Christians to attend sermons, studied the Hebrew and Arabic scriptures, lobbied against Muslim and Jewish participation in Christian society, wrote polemics, and engaged in public debates (Lat. disputationes). None of these techniques yielded much success, except among the Muslim slave population, who saw conversion as a step toward manumission.
In the fourteenth century religious and social boundaries became more rigid as increasingly elaborate codes of dress and conduct were prescribed for minority members. Pressure on Jews increased with Christian competition in the economic spheres that they had previously dominated as clerics, frustrated by their failure to rationally convert Jews, characterized them as obstinate, and as the population at large came to perceive marginal groups (including lepers and Muslims) as responsible for its misfortunes. Occasional outbreaks of violence, particularly during Eastertime, culminated in widespread pogroms in 1391. In the aftermath of these events many Jews converted out of either fear or opportunism, some secretly maintaining their beliefs as crypto-Jews (Sp. Marranos). Converts, however, remained marginalized by a society that distinguished between “old” and “new” Christians. In 1492, the Spanish kingdoms adopted policies that called for conversion or execution (with the option of exile in Castilian and Aragonese lands). Many Jews fled abroad, particularly to Muslim lands and the Netherlands; those who remained became a favorite target of the Inquisition.
Officially marginalized, Muslims occasionally rose in local revolts, which were sometimes responded to with mass deportations. Perceived as less of a threat, Mudéjars’ resistance to conversion did not tend to elicit the violent reaction that the Jewish presence did until the late fifteenth century. Following the fall of Granada in 1492, pressure increased, thanks in part to the machinations of Archbishop Cisnero of Toledo and the military threat posed by the Turks. The sixteenth century was characterized by persecution, expulsion, and forced conversion in Portugal (1497), Castile (1502), Navarre (1515), and Aragon and Valencia (1526). Later in the century, Inquisition and the prohibition of traditional culture prompted further revolts among the converts (Moriscos), while increasing reactionism in Spanish church and society led to the promulgation of decrees of expulsion from 1609. Over the following decade the Moriscos were exiled and sought refuge in North Africa and Ottoman territories.