The Jewish community in Spain was the largest and most important in the West for almost a thousand years, participating fully in cultural and political affairs with Christian and Muslim neighbors. Norman Roth traces the chain of events that led to mass conversions of Spanish Jews to Christianity in the fourteenth and fifteenth centuries, the rise of animosity against them, the establishment of the Inquisition, and finally, the 1492 Expulsion of the Jews from Spain.

Citing evidence from his extensive research of medieval documents, he firmly refutes the traditionally accepted story of "crypto-Judaism," which contends that the conversos were forced publicly to abandon their faith, while continuing secretly to maintain their Jewish traditions. Roth argues persuasively that the conversos were, in fact, sincere Christians.