This review brings together research in three areas of Anabaptist studies and the Radical Reformation. The first part focuses on 16th-century Anabaptism, re-examining the polygenesis model of Anabaptism articulated by Stayer, Packull and Depperman. The second part deals with the connections between Anabaptists and other Reformation dissenters, their marginalization as social groups and their relations with the intellectual movements of the age. The final section addresses historiographic and comparative issues of writing the history of marginalizaed groups, investigating some preconceptions which influence historians' approaches to Anabaptism and their implications for understanding other religious organizations.