The early expansion of Islam led in time to widespread conversions of Christians in conquered territories. In the later eleventh century, however, western Christendom was in turn launching offensives against Islam on several fronts. Territorial gains were made in various Mediterranean regions and, although by the end of the thirteenth century the Holy Land had been lost again, Sicily remained in Christian hands, and in the second half of the thirteenth century in the Iberian peninsula only Granada remained under Muslim control: the whole peninsula was under Christian rule before the end of the fifteenth century. This expansion was accompanied, especially in the thirteenth century, by attempts to convert Muslims and other non-Christians. Yet in the period from the late eleventh until the later fifteenth century some western Christians converted to Islam. The purpose of the present paper is to consider the situations that prompted the adoption of Islam, and the reasons for such conversions, although the evidence is usually insufficient to indicate exactly why a particular Christian became a Muslim: the preconceived ideas voiced in western sources about forced conversions can be misleading and, although a crude distinction might be made between conversions from conviction and those based on worldly considerations, motives did not necessarily always fit neatly into just one of these two categories. But obviously not all converts would have had an equal understanding of the nature of Islamic beliefs and practices. The response of western ecclesiastical and secular authorities to renegades will also be considered. Further conversions of Christian peoples who had already for centuries been living under Muslim rule will not be examined, but only the adoption of Islam by those whose origins lay in western Christian countries or who were normally resident in these, and by westerners whose lands were newly conquered by Muslim powers after the eleventh century; and the focus will be mainly, though not exclusively, on the crusader states and the Iberian peninsula.
The Perceived Attractions of Islam
Western commentators — most, though not all, were clerics — usually had difficulty in accepting that Christians could be won over by any perception [End Page 153] of true merit in the Islamic faith’s teachings and practices, since they themselves were convinced that there was none. In the early fourteenth century the anonymous author of the Memoria Terre Sancte wrote of apostates that “everyone should understand that their renouncing of the Christian faith was not because they believed or thought that the law of Muhammad was better than the Christian one,”1 and Symon Semeonis stated of renegades in Egypt that although many had adopted the Islamic religion, at heart they still embraced the Christian faith.2 John Manuel, the nephew of the Castilian King Alfonso X, claimed that the Islamic faith was in many ways so nonsensical and unreasonable that no one of any understanding would consider that it could lead to salvation.3
It was usually the weak and simple-minded who were thought to be vulnerable. Peter the Venerable, when asking St. Bernard in the mid-twelfth century to compose a refutation of Islam, wrote that, although Muslims might not be converted, it was necessary “to consider and provide for weak members of the Church, who are commonly led astray or even unthinkingly won over by trivial arguments.”4 In 1322 a provincial council at Valladolid expressed the fear that the simple-minded might be attracted to Islam, and Oldradus of Ponte also alluded to the possibility of the conversion of “simple” (simplices) Christians.5 [End Page 154]
It was thought that such people might be influenced by the superficial attractions of what was seen to be a lax religion. James of Vitry thus maintained in the early thirteenth century that some Christians went over to Islam to indulge in gluttony, dissipation, and obscene pleasures, and towards the end of that century the Franciscan Fidentius of Padua claimed that some were attracted by a desire for carnal pleasure, while Humbert of Romans, at one time head of the Dominican order, had a few years earlier sought to contrast the austere demands of his own faith with the...