"We have seen now that after the tenth century the most important centres of the Jewish diaspora were no longer in Babylonia or in the Islamic capital of Baghdad (which however remained the seat of the Gaonate and the Exilarch) but shifted westward to Egypt and Spain, and eastward to Khurasan, Central Asia and the frontier of Hind... Egypt, after the fall of Constantinople in 1204, virtually monopolized the Indian transit trade but the Jews were expelled from this trade and an association of Arab traders known as the karimi took over... All along the northern overland routes from India, in Sind and Afghanistan, the Babylonian-Persian Jewry spread and be­ came an important commercial intermediary between the Islamic world on the one hand and India and Central Asia on the other. Jewish settle­ment in this period rapidly increased here, until in the thirteenth century the Mongols brought Jewish involvement in trade and finance to a low pitch. It is quite clear that the elimination of the Jewish intermediary from the overland India trade virtually coincided in time with the elimi­nation of the Jews from the maritime trade between coastal western In­dia and Malabar and Egypt. In Malabar, Muslim traders superseded the Jewish and, to a lesser extent, Christian guilds. Jewish involvement in the trade between India and the Islamic lands of the Middle East, then, after reaching a peak in the tenth to eleventh centuries, eclipsed in the twelfth or thirteenth century - at the same time that the Jewish transition to Latin Christianity occurred. The simultaneousness of these developments appears to be no accident."