Medieval Jewish History 101
Jewish historians define the medieval period (or the Middle Ages) between the Muslim-Arab conquests in the early seventh century and the appearance of modern ideas regarding the economy, religious identity and social interaction, sometime around the mid-seventeenth century. This period is characterized by the geographic dispersion of the Jews, who lived under the rule of the two other monotheistic faiths, Christianity and Islam.
Under Islam, the laws governing Jewish life were set forth in the Pact of Omar. This contract, established in the seventh century, required non-Muslims to abide by a host of discriminatory regulations, such as rising in the presence of Muslims and dressing in distinctive garb. The medieval Islamic empire included, at various points, significant Jewish communities like Toledo, Constantinople, Salonika, and Jerusalem.
Jews living in Christendom--in places like Rome, Worms, Cracow, or, after, 1248, Spain--were subject to the laws of both church and state. Under Islam, there was no separation between church and state, so Jews expected uniformity from Muslim leaders. Under Christianity, the separation of church and state, coupled with the absence of unified religious law regarding Jews, led to arbitrary application of policy and punishment.
Early medieval Judaism was guided by the heads of the rabbinical academies (yeshivot), known as geonim. Decentralization of rabbinic Judaism paralleled the breakup of political unity in the Islamic empire in the eighth and ninth centuries. Thereafter, local academies and rabbis gained prominence.