After being educated in Belgium, Beauregard was general counsel of Savoie from the time of the annexation of the Duchy of Savoy to France on 14 June 1860, following the signature of the Treaty of Turin on 24 March 1860, after which he lived in Paris. He participated in the Franco-Prussian War (which took place between July 1870 to January 1871) as commander of the 1st "bataillon des mobiles de la Savoie", and he was wounded and taken prisoner during the Battle of the Lisaine in January 1871. From 1871 to 1876, he was a member of Parliament for Savoy.