Rhin-et-Moselle was a department of the First French Republic and First French Empire in present-day Germany. It was named after the rivers Rhine and Moselle. It was formed in 1797, when the left bank of the Rhine was annexed by France. Until the French occupation, its territory was divided between the Archbishopric of Cologne, the Archbishopric of Trier, and the Electorate of the Palatinate. Its territory is now part of the German states of Rhineland-Palatinate and North Rhine-Westphalia. Its capital was Koblenz.

The Electorate of Cologne, sometimes referred to as Electoral Cologne, was an ecclesiastical principality of the Holy Roman Empire that existed from the 10th to the early 19th century. It consisted of the Hochstift — the temporal possessions — of the archbishop of Cologne, and was ruled by him in his capacity as prince-elector. There were only two other ecclesiastical prince-electors in the Empire: the Electorate of Mainz and the Electorate of Trier. The archbishop-elector of Cologne was also arch-chancellor of Italy and, as such, ranked second among all ecclesiastical and secular princes of the Empire, after the archbishop-elector of Mainz, and before that of Trier.