Palatinate, The (German Pfalz, "palace"), the name used to designate the fief of the Palsgraves or Counts Palatine of the Rhine, who from the 11th century had their seat at Aix-la-Chapelle and ruled over a wide and productive area of 2,293 square miles, extending from Mayence to Treves. This constituted the Lower Palatinate, or Palatinate of the Rhine. In the 13th century the province passed into the Bavarian family by the marriage of Otho II. with Agnes, heir to the Suabian Palsgraves, and thus there came into existence an Upper Palatinate in Bavarian territory, with an area of 3,750 square miles, lying between Bavaria proper, Bohemia, and Nuremberg. In 1680 the two districts became separated, and until 1777 remained asunder, being then reunited under Charles Theodore. By the Treaties of Paris (1814-15) a fresh partition took place. Most of the Electoral or Lower Palatinate was given to Prussia, of which it still forms part, and a smaller share to Hesse-Darmstadt, whilst the Upper Palatinate passed into Rhenish Bavaria, with the exception of a small strip added to Baden.