Sometime in the first six months of 838, Bodo, a palace deacon at the court of Louis the Pious, converted to Judaism, changed his name to Eleazar and removed himself to Muslim Spain. The incident is well attested in various sources although the reasons for his abandonment of Christianity are not clearly given. In 840, a year after arriving in Spain, Bodo, now Eleazar, engaged in a debate with Álvaro of Córdoba, a Christian writer and scholar living in Muslim territory who claimed to be of Jewish ancestry. Their correspondence provides illuminating insights into the framework of cultural and religious experience of this period. Bodo's self-imposed exile from Christian society is also an important rejection of the Carolingian cultural programme, a voice of protest that was probably more widespread than Carolingian society would have us believe. What follows is partly an analysis of the main textual sources that brings into relief personal, social and political themes seen to lie behind the theolo-gical debates of the period. There is also an attempt to uncover aspects of Bodo's earlier life before his conversion.