These counts palatine of the Rhine would serve as prince-electors (Kurfürsten) from "time immemorial", and were noted as such in a papal letter of 1261; they were confirmed as electors by the Golden Bull of 1356.

The counts palatine of the Rhine held the office of imperial vicars in the territories under Frankish law (in Franconia, Swabia and the Rhineland) and ranked among the most significant secular Princes of the Holy Roman Empire.

Their climax and decline is marked by the rule of Elector Palatine Frederick V, whose coronation as king of Bohemia in 1619 sparked the Thirty Years' War.

After the 1648 Peace of Westphalia, the ravaged lands were further afflicted by the Reunion campaigns launched by King Louis XIV of France, culminating in the Nine Years' War (1688–97).

Up to the tenth century, the Frankish empire was centered at the royal palace (Pfalz) in Aachen, in what had become the Carolingian kingdom of Lotharingia.

While his Palatine authority operated over the whole of Upper Lorraine, the feudal territories of his family were instead scattered around south-western Franconia, including parts of the Rhineland around Cologne and Bonn, and areas around the rivers Moselle and Nahe.

In continual conflicts with the rivalling Archbishops of Cologne, he changed the emphasis of his rule to the southern Eifel region and further to the Upper Rhine, where the Ezzonid dynasty governed several counties on both banks of the river.

The first hereditary Count Palatine of the Rhine was Conrad, a member of the House of Hohenstaufen and younger half-brother of Emperor Frederick Barbarossa.

In the Golden Bull of 1356, the Palatinate was recognized as one of the secular electorates, and given the hereditary offices of archsteward (German: Erztruchseß, Latin: Archidapifer) of the Empire and imperial vicar (Reichsverweser) of Franconia, Swabia, the Rhine, and southern Germany.

This initiated the 1618–1648 Thirty Years' War, one of the most destructive conflicts in human history; it caused over eight million fatalities from military action, violence, famine, and plague in the vast majority in the German states of the Holy Roman Empire.

[4] Frederick was evicted from Bohemia in 1620 following his defeat by the forces of Ferdinand II, Holy Roman Emperor, at the Battle of the White Mountain.

However, he was outmaneuvered by Leopold I, Holy Roman Emperor, whose third wife was Eleonore-Magdalena of Pfalz-Neuburg, eldest daughter of Philip William, a Catholic who was the closest male heir in the direct line.

[5] When France invaded the Palatinate in September 1688 to enforce its claim, these wider connections meant the conflict rapidly escalated, leading to the outbreak of the Nine Years' War.

Like his father, he was a Catholic, which under the 1555 Peace of Augsburg meant the Protestant majority in the Palatinate was theoretically obliged to convert to Catholicism.

In 1799 Elector Charles Theodore died and the territory was inherited by the Duke of Palatine Zweibrücken, uniting all the Wittelsbach lands.

[10] Those on the right were taken by the Elector of Baden, after the 1805 Peace of Pressburg dissolved the Holy Roman Empire; the remaining Wittelsbach territories were united by Maximilian Joseph as the Kingdom of Bavaria.