Characters representing various sins and vices became the stars of their respective theatrical traditions in the course of the late medieval and early modern period in both the Low Countries and England. This study assesses the importance of such characters, and especially the English Vice and Dutch sinnekens, for our understanding of medieval and sixteenth-century Dutch and English drama by charting diachronic developments and through synchronic comparisons. The analysis of the functions as well as theatrical and meta-theatrical aspects of these characters reveals how these plays were conditioned by their literary and social setting. It sheds invaluable light on the subtly divergent appreciation of the concept of drama in these two regions and on their different use of drama as a didactic tool. In a wider perspective this study also investigates how the moral plays and their negative characters reflect the changes in the intellectual and religious climate of the fifteenth and sixteenth centuries.