Its commander-in-chief from 5 October 1800 to 1 April 1801 was Etienne-Jacques-Joseph-Alexandre Macdonald, during which time it operated as the hinge between the Army of Italy under Brune and the Army of the Rhine under Jean Moreau, crossing the Splügen (4 December) and capturing Trento (6 January).

Its first taste of combat occurred in December 1800, when they crossed the Alps, opposing Austrian Forces.

The First Consul, Napoleon, also crossing the Alps, ordered that General Macdonald thrust forwards and occupy Austrian Tyrol.

But Macdonald, following Napoleon's orders, moved on and encountered Austrian Forces at Mincio and routed them, turning back the frontier.

After the Battle of Hohenlinden, the Army was shortly disbanded in 1801 to later form part of the Grande Armée.