Early fortifications had been erected around around 1000 BCE in the vicinity of present Koblenz, on the Festung Ehrenbreitstein hill on the opposite side of the Moselle.

Roman troops commanded by Julius Caesar in 55 BCE had reached the Rhine and built a bridge between present Koblenz and Andernach.

Drusus, in about 9 BCE, fortifies the site site, which lies between the present-day German cities of Bonn and Mainz at the confluence of the Mosel (Moselle) and Rhine rivers in the modern German state of Rhineland-Palatinate.

The city of Koblenz, with the fall of the Western Roman Empire, had been conquered by the Franks and become a royal seat.

After the division of Charlemagne's empire in 814, it had been included in the lands of his son Louis the Pious.

It is assigned in 837 to Charles the Bald.

The church of Saint Castor (Kastorkirche) is constructed here in 836-37.

The city of Koblenz is given by the emperor Henry II to the archbishop and prince elector of Trier after receiving a charter in 1018.

It will remain in the possession of his successors until the end of the eighteenth century, having been their main residence since the seventeenth century.

Dumouriez had prepared an immediate invasion of the Austrian Netherlands, where he had expected the local population to rise against Austrian rule.

However, the revolution has thoroughly disorganized the army, and the forces raised had been insufficient for the invasion.

An allied army under Charles William Ferdinand, Duke of Brunswick, assembles at Koblenz on the Rhine while the revolutionary government frantically raises fresh troops and reorganizes its armies.