Text in German. Hartberg's legal sources from the 12th to the beginning of the 19th century offer a unique insight into the early absolutist state-building process of the Habsburg type in the 17th century, as well as the development of municipal law, when Hartberg lost the status of a princely city and opposed the claims of the patrimonial city ruler to the extreme with reference to the old privileges and appealed in vain to the sovereign. In the course of the dispute, which culminates in the murder of the town clerk, all relevant legal concepts, including Jean Bodin's theory, emerge with astonishing clarity. Hartberg's city law sources provide a unique insight into the upheavals and state-building process in the early 17th century.