The principality was initially created as an ecclesiastical electorate for Archbishop Karl Theodor von Dalberg, the Elector-Archchancellor of the Empire and the former Archbishop of Mainz, due to the annexation of Mainz itself by the French following the Treaty of Lunéville.

Dalberg also acquired the newly created Principality of Aschaffenburg along the Main river.

The principality lost its status as an electorate in 1806 with the dissolution of the Holy Roman Empire and became part of the Confederation of the Rhine later that year.

In the Treaty of Paris, Dalberg conceded Regensburg to the Kingdom of Bavaria, which formally incorporated the city on 22 May 1810.

In return for conceding Regensburg, Dalberg was granted Hanau and Fulda, which he combined with the Principality of Aschaffenburg to create the Grand Duchy of Frankfurt.