Sahuc became a member of the Tribunat in 1801 and was an eager supporter of Napoleon Bonaparte, voting to establish the First French Empire. In 1803 he became a "chevalier de l'empire", then in 1804, a commander of the Légion d'Honneur. In the War of the Third Coalition, he served in a division that included the 15th and 17th Dragoon Regiments, which lost their eagles and many troopers at the Battle of Haslach-Jungingen on 11 October 1805. The 18th and 19th Dragoons of the division also fought on 14 October 1805 in the Battle of Elchingen. On 2 December 1805, Sahuc fought at the Battle of Austerlitz in François Antoine Louis Bourcier's 4th Dragoon Division. The 2,500-strong division included the 15th, 17th, 18th, 19th, and 27th Dragoon Regiments and three cannon. The brigadiers were Sahuc and Jean Baptiste Antoine Laplanche.