Imperial circle
During the early modern period, the Holy Roman Empire was divided into imperial circles (Latin: Circuli imperii; German: Reichskreise [ˈʁaɪçsˌkʁaɪzə]; singular: Circulus imperii, Reichskreis [ˈʁaɪçsˌkʁaɪs]), administrative groupings whose primary purposes were the organization of common defensive structure and the collection of imperial taxes. They were also used as a means of organization within the Imperial Diet and the Imperial Chamber Court.