Mediatized (from Mediatization) refers to a formerly souvereign non-eccelesiastic principality within the Holy Roman Empire that has has lost its immediate souvereignty (Reichsunmittelbarkeit = Imperial immediacy) within the Empire and been incorporated into another realm -- an event with wide application in Germany in 1803 (Reichsdeputationshauptschluss ), following Napoleon's victory over the Austrian and German princes and the dissolution of the Holy Roman Empire in 1806. It paralleled the abolition (secularization) of eccelesiastic souvereignty and territorial property rights effected at the same time.
The constitution (Bundesakte ) of the German Union (Deutscher Bund ) of 1815 retained and confirmed these provisions of the 1806 Rheinbund constition, but left certain rights to the mediatized princes (e.g., first instance jurisdiction). This remained in effect until the revolution of 1848/49 and in a number of cases even longer.
