His troops were ordered to the front after the Montenotte Campaign forced the Kingdom of Sardinia-Piedmont to sue for peace.
Bonaparte formed an advanced guard by combining 3,500 converged foot grenadiers and carabiniers with 1,500 cavalry.
Assigning Dallemagne to command the advanced guard,[3] Bonaparte sent it marching along the south bank of the Po River to turn Austrian General Johann Beaulieu's left flank.
Supported by the division of Amédée Laharpe, Dallemagne crossed to the north bank and defeated the Austrians at the Battle of Fombio on 7–8 May 1796.
Along with André Masséna, Jean Lannes, Louis Berthier, and Jean-Baptiste Cervoni, he bravely rallied the troops to cross the bridge after cannon fire caused them to hesitate.
[5] In July, Bonaparte detached Dallemagne's brigade from Jean Serurier's division and sent it to reinforce Masséna.
On 3 August, Ott repulsed his attack on Gavardo but this action allowed Masséna to mass against and destroy Joseph Ocskay's brigade.
After the Battle of Bassano and the combat of La Favorita, he led an attack to drive the Austrian garrison back within the fortress on 24 September.