The book consists of ten chapters that are based mainly on new sources. The chapters discuss the economic activities of Jews and non-Jews in Constantinople and Smyrna during the long eighteenth century (1700-1820). The chapters also contain information relating to Salonica. The primary material for the volume was the Levant Company's official correspondence exchanged between its administration and employees, political authorities in England and the Sublime Porte. This work is based also on archival research of Jewish sources, mainly the Responsa literature, in order to understand the various topics under discussion. Jews frequently appear in these studies due to their place in local and international trade and because of the close ties between Jewish brokers and European merchants. The ten chapters of the book are based on undisclosed documentation and deal mainly with the Jews of Constantinople and secondarily also with the Jews of Smyrna, with slight reference also to the Jews of Salonica. The purpose of the research is to point out the deep involvement of the Jews in these cities in trade and money lending, and to study the connections of Jewish brokers, merchants, and Sarrafs in the above cities with the British merchants in the period under discussion.