At the turn of the 16th century, the standing of Jews in the Bohemian lands underwent a rapid transformation in terms both of their legal status and the opportunities available to them to engage in economic enterprise. Life within Bohemian Jewish communities was also substantially influenced by accounts of Jews from some of the royal cities. Certain settlements of the period passed temporarily out of existence, while others experienced revitalization. As in the Middle Ages, the most important communities of the time were centred in royal cities, namely Prague and Kolín (Köln an der Elbe). Liaisons between some of the families, their mutual support in providing large loans, and their ties to other Jewish communities in Bohemia make it possible, at least in part, to reconstruct their business and social strategies, such as the formation of alliances. The aim of this contribution is to trace some prominent Jewish families working and conducting business during the studied period in Prague and other royal cities, their business networks, migration within Bohemia, and their liaisons with other notable Jewish families in the Holy Roman Empire.