Mont-Blanc was a department of the First French Empire. It was named after Mont Blanc, the highest mountain in Western Europe, which marks the border between France and Piedmont. It was formed in 1792, when the Savoy region, (part of the Kingdom of Sardinia) was occupied by the French. The department ceased to exist following Napoleon's defeat at Waterloo; the territory was restored to its former rulers.
During the night of 21 September 1792, French troops under General Moutesquiou launched a surprise attack on the Duchy of Savoy, which at the time was a dependent territory of the Kingdom of Sardinia. The king, who was in residence at Chambéry, accompanied by his army, numerous administrators and clergy, fled across the Alps to his Piedmontese lands.
At the end of October, the so-called Assembly of the Allobroges (who named themselves after an ancient people thought to have occupied the region two thousand years earlier) convened in the cathedral at Chambéry. Their agenda followed the revolutionary script that by now was becoming familiar across France, as they declared an end to despotism, forced labour and the hated salt tax. The meeting was dissolved on 29 October 1792, but not before passing a resolution expressing the wish for The Duchy of Savoy to be incorporated into revolutionary France. Two deputies, named François Amédée Doppet and Simond, were mandated to convey this wish to the revolutionary National Convention in Paris.