1911 Encyclopædia Britannica/Mediatization
MEDIATIZATION (Ger. Mediatisierung, from Lat. mediatus, mediate, middle), the process by which at the beginning of the 19th century, a number of German princes, hitherto sovereign as holding immediately of the emperor, were deprived of their sovereignty and mediatized by being placed under that of other sovereigns. This was first done on a large scale in 1803, when by a recess of the imperial diet many of the smaller fiefs were mediatized, in order to compensate those German princes who had been forced to cede their territories on the left bank of the Rhine to France. In 1806 the formation of the Confederation of the Rhine involved an extension of this mediatizing process, though the abolition of the empire itself deprived the word “mediatization” of its essential meaning. After the downfall of Napoleon the powers were besieged with petitions from the mediatized princes for the restoration of their “liberties”; but the congress of Vienna (1815) further extended the process of mediatization by deciding that certain houses hitherto immediate (i.e. Salm, Isenburg, Leyen) should only be represented mediately in the diet of the new Confederation. On the other hand, at Aix-la-Chapelle (1818) the powers, in response to the representations of the aggrieved parties, admonished the German sovereigns to respect the rights of the mediatized princes subject to them. Of these rights, which included the hereditary right to a seat in the estates, the most valued is that of Ebenbürtigkeit (equality of birth), which, for purposes of matrimonial alliance, ranks the mediatized princes with the royal houses of Europe.
See August Wilhelm Heffter, Die Sonderrechte der Souveränen und der Mediatisirten, vormals reichsständischen Häuser Deutschlands (Berlin, 1871). The mediatized families are included in the Almanack de Gotha.