In various capacities, he served as Archbishop of Mainz, Prince of Regensburg, Arch-Chancellor of the Holy Roman Empire, Bishop of Constance and Worms, Prince-Primate of the Confederation of the Rhine[1] and Grand Duke of Frankfurt.

[5] As statesman, Dalberg was distinguished by his patriotic attitude, whether in ecclesiastical matters, in which he leaned to the Febronian view of a German national church, or in his efforts to galvanize the atrophied machinery of the Holy Roman Empire into some sort of effective central government of Germany.

In the Final Recess of the Extraordinary Imperial Deputation of 1803, it was decided to compensate German princes for their losses to France by distributing the church land among them, so Dalberg lost a couple of territories there (among other things, Constance), though (due to his prominent position of the Arch-Chancellor of the Empire,[2] and perhaps also due to his personality and skilled diplomacy), he would be the only spiritual prince to retain at least some territory for temporal government: the Mainzian lands around Aschaffenburg, the Reichsstadt (Free Imperial City) of Wetzlar (with the rank of a Countship) and the Principality of Regensburg containing the Imperial City, the prince-bishopric, and some independent monasteries.

This was, of course, the decision of a state authority which, in its spiritual part, could not take effect until ratified by the Pope; in any case, Regensburg's bishop, Josef Conrad of Schroffenberg-Mös, was still alive at the time.

This was opposed by the Lutheran town council, until 1811, when Dalberg issued a proclamation ending the requirement that Jews live in the ghetto or pay special taxes.

[citation needed] On 14 January 1806 he performed the wedding of Eugène de Beauharnais, Napoleon's stepson, and the Bavarian Princess Augusta of Bavaria.