The palsgraves of the Rhine originally had their seat in Aix-la-Chapelle. In the 11th century the country called the Palatinate belonged to them as an hereditary fief, in virtue of which they ranked among the foremost princes of the empire. In 1156, after the death of Palsgrave Hermann III. without heirs, the Palatinate was granted by the emperor Frederick I. to his step-brother Duke Conrad of Swabia. Conrad was succeeded by his son-in-law, Duke Henry of Brunswick, the eldest son of Henry the Lion. In the contest for the crown between Otho IV. and Frederick II., Henry took part with Otho IV., his brother; and in 1215 Frederick II. punished him by putting him to the ban of the empire, and by granting the Palatinate to Louis, duke of Bavaria. Louis was never able to assert his claims with complete success; but his son Otho II. married Agnes, the daughter and heiress of Henry, and thus the Palatinate passed into the hands of the Bavarian family. In 1256 the whole territory of the family was divided between Louis II. and Henry, Otho’s sons,—Louis II. obtaining the Palatinate and Upper Bavaria, and Henry Lower Bavaria. The possessions of Louis II. were inherited in 1294 by his two sons, Rudolph I. and Louis, the Palatinate and the electoral dignity going to the former, while the latter (who ultimately became emperor) received Upper Bavaria, to which Lower Bavaria was afterwards added. The claims of Louis to the imperial crown were contested by Frederick the Fair, duke of Austria; and, as Rudolph I. supported Frederick, his brother deprived him of his lands, which were then held in succession by Rudolph’s three sons, Adolph, who died in 1327, Rudolph II., who died in 1353, and Rupert I., who died in 1390. Rudolph II. concluded a treaty with the emperor Louis, whereby the electoral vote was to be delivered alternately by Bavaria and by the Palatinate: but the emperor Charles IV., in return for a part of the Upper Palatinate, conferred on Rupert I. and his. heirs the exclusive right to the electoral dignity. Rupert I., in 1386, founded the university of Heidelberg. He was succeeded by his nephew, Adolph’s son, Rupert II., whose son and successor, Rupert III., was elected emperor in 1400. After the death of Rupert III. in 1410, his hereditary territories were divided among his four sons, Louis III., John, Stephen (who became palsgrave of Simmern and Zweibrücken), and Otho. The families of John and Otho soon died out, and the last representative of the line of Louis III.—Otho Henry—died in 1559. The lands of Otho Henry and the electoral dignity then passed to Frederick III., of the Simmern line; and Frederick III. marked an important epoch in the history of the electorate by definitely associating himself and his house with the Reformed or Calvinistic Church. His immediate successors were Louis VI., Frederick IV., and Frederick V. The latter, in 1619, rashly accepted the crown of Bohemia; and the result was that, after his expulsion from his new kingdom, the Palatinate was given by the emperor Ferdinand II. to Maximilian, duke of Bavaria. In virtue of the treaty of Westphalia, Charles Louis, Frederick V.’s son, who died in 1680, received back the Lower Palatinate, and in h⅛⅛ favour an eighth electorate was created, with which was associated the office of lord high treasurer (Erzschatzmeisteramt). The house of Bavaria retained the Upper Palatinate, with the office of arch-sewer (Erztruchsessamt), and with the rank which had formerly been held in the electoral college by the counts palatine; but it was arranged that, if the male line of Bavaria died out, the lands and rights which had belonged to the rulers of the whole Palatinate should be restored to their descendants. Charles, Charles Louis’s son, who died in 1685, was the last representative of the Simmern line. The electoral dignity and the lands connected with it then passed to Charles’s kinsman, Philip William, of the Neuburg line, which sprang from Louis the Black, the second son of Stephen, son of Rupert III. Of Louis the Black’s two grandsons, Louis and Rupert, the latter was the ancestor of the Veldenz line, which died out in 1694, while from the former sprang all other palatine lines—the Neuburg line, the Neuzweibrücken line, the Birkenfeld line, the Sulzbach line. Philip William, of the Neuburg line, died in 1690, and was succeeded by his son John William, who in 1694 inherited Veldenz, and during the war of the Spanish succession received the Upper Palatinate and all the ancient rights of his house. At the conclusion of the war, however, both rights and lands were restored to the elector of Bavaria. In 1716 John William was succeeded by his brother Charles Philip; and with Charles Philip, who died in 1642, the Neuburg line came to an end, and the Lower Palatinate was inherited by Charles Theodore, of the Sulzbach line. In 1777 the male line of Bavaria became extinct by the death of the elector Maximilian Joseph; and then, in accordance with the treaty of Westphalia, the Upper Palatinate and the Lower Palatinate were reunited, and the palsgrave resumed the office of arch-sewer and the ancient place of his family in the electoral college, while the office of lord high treasurer was transferred to the elector of Brunswick. The successor of Charles Theodore, who died childless in 1799, was Maximilian Joseph, duke of Zweibrücken. By the treaty of Lunéville in 1801 his territories were divided, the part which lay on the left bank of the Rhine being taken by France, while portions on the right bank were given to the grand-duchy of Baden, to Hesse-Darmstadt, to the prince of Leiningen-Dachsburg, and to Nassau. By the treaties of Paris concluded in 1814 and in 1815, the palatine lands on the left bank of the Rhine were restored to Germany, the larger part of them being granted to Bavaria, and the rest to Hesse-Darmstadt and Prussia. The Prussian part of the Palatinate is in the Rhine province; the Hesse-Darmstadt part is included in the province of Starkenburg and Rhine Hesse; the Bavarian part is known as Rhenish Bavaria; and the Baden part is in the Lower Rhine district, which in 1865 was divided into the districts of Mannheim, Heidelberg, and Mosbach.

See Hausser, Geschichte der rheinischen Pfalz, 1845; Nebenius, Geschichte der Pfalz, 1874.