Its troops were maintained by Württemberg for its national defence and as a unit of the Swabian Circle (district) of Holy Roman Empire, the Confederation of the Rhine, the German Confederation and finally of the Army of German Empire. In addition, particularly in the 18th century, there were also regiments that were lent to other dukes and foreign powers. This practice was often criticized as "soldier trading" or "Soldatenhandel"; a form of mercenary service.