Excerpts from Books and Wikipedia
"On March 31, 1492, less than three months after the fall of Granada, Isabella and Ferdinand issued the Edict of Alhambra, which ordered the mass expulsion of all Jews from Spain who refused to convert to Christianity. . . . [Estimated number was 165,000 to 800,000.] There had long been a sizable Jewish community on the Iberian Peninsula, and they had generally enjoyed good relations with the Muslim rulers, but their position had worsened with the spread of the Christian Reconquista. By 1300 Jews were required to wear a distinctive badge, and there were violent anti-Jewish riots in 1348 and 1391. . . . The expulsion of the Jews was regarded inside Spain as a triumph for the Catholic religion, but the chief effect was to deprive the country of some of its most economically successful and important citizens." [Furtado: 1001 Days]