For the most part, then, Jews and Christians lived as prosperous minorities in the classical Islamic empires of the Umayyads of Damascus and Spain and the Abbasids of Baghdad, preserving their religions and freedoms within their own religiously-based communities and paying a special poll tax called harac [haraj] or cizye [jizya] in return for the protection of the Muslim rulers and exemption from military service while living with great comfort and prosperity. There were limitations, there were some marks of discrimination, so that one could say that Jews and Christians were not as equal as Muslims, but compared to the active persecution to which Jews were subjected in the Christian lands of Europe, the world of Islam was paradise for them .
 On the Jews in Islamic Spain in particular see Eliyahu Ashtor, The Jews of Moslem Spain (Philadelphia, 1973).
Professor Justin McCarthy (Professor of History, University of Louisville) writes:
"For religious and practical reasons the Ottoman government protected the religious freedom and religious autonomy of its people. .. For more than five hundred years religious communities kept their faiths and their identities. In contrast to the religious persecution in Europe in the same period, the Ottoman practice of religious toleration is especially noteworthy... Nowhere in the long history of the Ottoman Empire is there any example of a government plan to make all the population Muslims."
Greek author-historian Nikos Stavroulakis writes:
"By the third quarter of the 15th century the Ottoman Empire had supplanted the Byzantine. Ottoman policy toward minorities was based on Islamic Law, which recognized both Jews and Christians as a separate millet (nation) with religious and, to an extraordinary extent, legal autonomy within their own communities. This tolerant millet system encouraged the immigration of Jews from Europe who had been feeling the brunt of Christian persecution, notably, in the late 15th century, in Spain."
Source: Athens-Auschwitz (by Errikos Sevillias), Translated and Introduced by Nikos Stavroulakis, Lycabettus Press, P.O. Box 17091, 100 24 Athens, Greece, 1983.
Norman Daniel, a prominent scholar of American philanthropy in the Middle East, writes:
".. during much of the nineteenth century the Christian subjects of Turkey had enjoyed a degree of religious freedom that was not accorded to dissenters from the established faith in some of the more enlightened kingdoms of Europe."
Source: Norman Daniel, American Philanthropy in the Near East. 1820–1960 (Athens, Ohio: Ohio University Press, 1970), 161.