Elements of the armies that were later formed into the Army of the Rhine and Moselle participated in the conquest of the Netherlands and the siege of Luxembourg. The various elements of the army won a victory at the Battle of Fleurus on 16 June 1794. Shortly after Fleurus, the position of the First Coalition in Flanders collapsed and the French armies overran the Austrian Netherlands and the Dutch Republic in the winter of 1794–1795. French and Coalition military strategy subsequently focused on the Rhine river as the principle line of defense: for each side, control of the opposite bank or, at least, the river's principal crossings, was the basis of defensive strategy.
