 The Rhine Campaign of 1795 ( April 1795 to January 1796 ) saw two Habsburg Austrian armies under the overall command of François Sébastien Charles Joseph de Croix , Count of Clerfayt defeat an attempt by two Republican French armies to cross the Rhine River and capture the Fortress of Mainz . At the start of the campaign the French Army of Sambre @-@ et @-@ Meuse led by Jean @-@ Baptiste Jourdan confronted Clerfayt 's Army of the Lower Rhine in the north , while the French Army of Rhin @-@ et @-@ Moselle under Jean @-@ Charles Pichegru lay opposite Dagobert Sigmund von Wurmser 's Army of the Upper Rhine in the south . In August Jourdan crossed and quickly seized Düsseldorf . The Army of Sambre @-@ et @-@ Meuse advanced south to the Main River , completely isolating Mainz . Pichegru 's army made a surprise capture of Mannheim so that both French armies held significant footholds on the east bank of the Rhine . The French fumbled away the promising start to their offensive . Pichegru bungled at least one opportunity to seize Clerfayt 's supply base in the Battle of Handschuhsheim . With Pichegru strangely inert , Clerfayt massed against Jourdan , beat him at <unk> in October and forced most of the Army of Sambre @-@ et @-@ Meuse to retreat to the west bank of the Rhine . About the same time , Wurmser sealed off the French bridgehead at Mannheim . With Jourdan temporarily out of the picture , the Austrians defeated the left wing of the Army of Rhin @-@ et @-@ Moselle at the Battle of Mainz and moved down the west bank . In November , Clerfayt gave Pichegru a drubbing at <unk> and successfully wrapped up the Siege of Mannheim . In January 1794 , Clerfayt concluded an armistice with the French , allowing the Austrians to retain large portions of the west bank . During the campaign Pichegru entered into traitorous contact with French Royalists . It is debatable whether Pichegru 's treason or his bad generalship was the actual cause of the French failure . 
