Emmerich was the nephew of Karl Theodor von Dalberg, arch-chancellor of the Holy Roman Empire, Prince primate of the Confederation of the Rhine and Grand-Duke of Frankfurt.

[1] Dalberg was at Vienna in the Imperial Chancellery when the stance of his uncle, who had taken the French side, ended his diplomatic career with the Austrian court.

After the Treaty of Lunéville (9 February 1801) between the French Republic and Francis II, Holy Roman Emperor, he was accredited to Paris as minister of the Margrave of Baden.

He negotiated the marriage of the young Charles, Grand Duke of Baden, with Princess Stéphanie de Beauharnais, niece of the Empress Josephine.

[1] After the Treaty of Vienna in 1809, Dalberg was naturalized as a French citizen and charged with negotiating Napoleon's marriage with Marie Louise of Austria.