When Daniel Swetschinski's dissertation appeared in 1980, it immediately became an indispensable work. It was a wide-ranging, clearly-ordered synthesis of scholarship on the Portuguese—Jewish community of Amsterdam in the seventeenth-century, incorporating some important original research. It surveyed the community's legal, demographic, economic, and institutional history, with a brief chapter on certain aspects of its cultural life. Its most original contribution was a detailed study of demographic data gleaned from the Amsterdam puyboecken, the municipal registers of intended marriages. On the basis of these records, Swetschinski charted in detail the immigration to Amsterdam of ex-conversos with origins in the Iberian Peninsula. His examination of the community's institutional life relied to a considerable extent on existing studies in Dutch, but also incorporated his own archival work, and it raised important questions about the structure of the community. Moreover, at a time when this was the exception rather than the rule, it dealt with the Portuguese Jews in an unsentimental, unromanticized fashion. The dissertation was far from exhaustive—a task beyond the reach of any young scholar—but it was a valuable contribution to Jewish communal history.