The Expulsion of the Jews from Spain, formalized by the Alhambra Decree of March 31, 1492, was a royal edict issued by the Catholic Monarchs Ferdinand II of Aragon and Isabella I of Castile ordering all unconverted Jews to leave their kingdoms and territories by the end of July that year, unless they converted to Christianity. Motivated by a desire for religious unity following the completion of the Reconquista and amid fears that unconverted Jews were influencing conversos (Jewish converts to Christianity) to revert to Judaism, the decree brought to an end more than a millennium of Jewish presence in the Iberian Peninsula. It also ranks among the most consequential events in Spanish and Jewish history.
In the decades before 1492, successive crises had already thinned Spain's Jewish population through violence, forced conversion, and legal discrimination. In the aftermath of the 1391 massacres, large numbers of Jews converted to Catholicism. Continued attacks produced about 50,000 additional conversions by 1415. Authorities suspected that some conversos continued to practice Judaism in secret; concerns over such "Judaizing" helped motivate the creation of the Spanish Inquisition in 1478, which investigated cases of heresy and, in some instances, used torture and imposed penalties up to execution for the unrepentant. Growing limpieza de sangre ("purity-of-blood") statutes in the 15th century further stigmatized "New Christians" of Jewish descent.