In 1803, when all ecclesiastic states in Germany were abolished, Fritzlar was incorporated, together with Naumburg, as the nominal Principality of Fritzlar into the Electorate (principality) of Hesse-Kassel (Kurhessen or Hesse-Cassel). In 1821 it became the administrative center of the district (Kreis) Fritzlar. Hesse-Kassel in turn was annexed by Prussia in 1866, following the Austro-Prussian War in which the Elector had sided with Austria and Briain. In 1932 the district was merged with the neighboring district of Homberg to form the district of Fritzlar-Homberg.