Arnulf's younger son, Arnulf II., continued the struggle against Otto I., and sometime before his death in 954 was made count palatine in Bavaria.
During the 15th century a war with the count palatine of the Rhine deprived Margrave Charles I.
His successor was his kinsman, Charles Theodore, count palatine of Sulzbach, a cadet of the Zweibriicken-Neuburg line, and now with the exception of one or two small pieces the whole of the Palatinate was united under one ruler.
Rhenish Franconia gradually became a land of free towns and lesser nobles, and under the earlier Franconian emperors sections passed to the count palatine of the Rhine, the archbishop of Mainz, the bishops of Worms and Spires and other clerical and lay nobles; and the name Franconia, or Francia orientalis as it was then called, was confined to the eastern portion of the duchy.
Above the village are the ruins of the castle of Rheingrafenstein (12th century), formerly a seat of the count palatine of the Rhine, which was destroyed by the French in 1689, and those of the castle of Ebernburg, the ancestral seat of the lords of Sickingen, and the birthplace of Franz von Sickingen, the famous landsknecht captain and protector of Ulrich von Hutten, to whom a monument was erected on the slope near the ruins in 1889.
This line became extinct on the death of Count Eberhard (1393), who in 1385 had sold half his territory to the count palatine of the Rhine, and held the other half as his feudatory.
In 1666 the great elector, Frederick William of Brandenburg, made with William, count palatine of Neuburg, a treaty of mutual succession to the duchies, providing that in case the male line of either house became extinct the other should inherit its lands.
The archbishop of Cologne, the elector of Brandenburg and his brother the archbishop of Mainz were for instant outlawry, while the elector of Saxony, who was resolved to protect Luther, had great influence with the archbishop of Trier and the Count Palatine of the Rhine.
It was settled in 1614 by a partition, under which Berg, with Jiilich, was assigned to the count palatine of Neuburg, in whose line it remained till 1742, when it passed to the Sultzbach branch of the house of Wittelsbach.
His action in abolishing all tolls established on the Rhine since 1250, led to the formation of a league against him by the Rhenish archbishops and the count palatine of the Rhine; but aided by the towns, he soon crushed the rising.