Under the French Revolution, the pace of Dallemagne's promotions quickened. He became sous-lieutenant in September 1791, lieutenant in June 1792, and captain that September. In late 1793, he fought at the Siege of Toulon, winning promotion to general of brigade. After a brief stint in the Army of the western Pyrenees, he transferred to the Army of Italy in early 1794. That year he captured the Col de Tende. He also served in the 1795 campaign.[2]
In April 1796, Dallemagne commanded a brigade in Francois Macquard's division. 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.[4] Two days later, he led his troops at the successful Battle of Lodi. 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.[6] He led his soldiers with distinction at the Battle of Lonato. On 31 July, his troops helped recover Lonato from Peter Ott's Austrians. On 3 August, Ott repulsed his attack on Gavardo but this action allowed Masséna to mass against and destroy Joseph Ocskay's brigade. Two days later, Dallemagne fought at the Battle of Castiglione. He received promotion to general of division on 15 August.
Dallemagne held important posts during the Siege of Mantua. 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.[7] During the Battle of Arcole campaign, Dallemagne led a small division under the orders of Charles Kilmaine.[8] In the Battle of Rivoli campaign, he commanded a division under Serurier in the siege. A division came under his orders in the invasion of Austrian during the spring of 1797.
Beginning in 1797, Dallemagne held commands at Boulogne, Ancona, Rome, and Mainz. He asked to be retired from the army in December 1799, which became official in 1802. Meanwhile, he began a political career and served as a deputy in the Corps législatif from 1802 to 1813. Dallemagne married Jeanne Christine Gaudet (1785–1849) on 19 February 1800. They had two sons, Clément and Claudius.
