This study delineates and investigates the structure of crime in the city of Rome in the late 16th century, with research methods developed in Britain, America and France applied here for the first time to Italy. The objective of this study is less to point up the interaction between delinquency and ruling class repression than to inquire into the causes behind the obviously endemic and staggeringly high rate of crimes of violence in Rome, which far exceeds anything to be found in contemporary crime records for other cities of the period.