The Tolerant Migrant Cities project examines migrants through the eyes of the courts in the highly urbanized coastal provinces of the Netherlands (Holland) between 1600 and 1900. It aims to reveal patterns of continuity and change in: (1) Treatment of migrants by criminal courts; and (2) Violence and conflicts between migrants and native born. Holland is an excellent case study for various reasons: between 1600 and 1830 it was characterized by exceptionally high immigration and in the course of the period the proportion and types of migrants changed considerably. The research is feasible because of the ample availability of legal sources, which have hardly been examined. To what extent does the image of tolerant Dutch cities in Holland need to be adjusted and what are the implications for the present?