‘You have to die in Piedmont!’ An old folk song, still played in the western Alps, speaks about the French regiments that were incoming from the Mongeneve Pass in order to attack a combined Austro-Sardinian force entrenched on the Assietta Plateau at 2,500 meters (about 8,200 ft) of elevation in the Cottian Alps, which controls two main roads from France to the Kingdom of Sardinia’s capital, Turin. The battle occurred 19 June 1747, and was the bloodiest single day battle not only of the War of Austrian Succession (1740-1748) in Italy, but also of the whole military history of the Alps, and of mountain warfare in general.The strategic goal of the French offensive was the siege and the capture of the Fort of Exilles, a fortress in the Susa Valley on the road from Briançon to Turin. An army of about 20,000 soldiers under the command of Louis Charles Armand Fouquet de Belle-Isle (called the Chevalier de Belle-Isle, the younger brother of the Marshal de Belle-Isle) was divided into two corps: one went down the Moncenisio towards Exilles, while the other advanced towards the Chisone Valley, in order to reach the Assietta ridge from the south side. Having predicted that the French would move through it, the King Charles Emmanuel III of Savoy had fortified the area with an entrenched camp garrisoned with 7,000 men of 13 infantry battalions: 9 Sardinian, and 4 Austrian.French intelligence discovered that the allied forces were fortifying the pass, while the main Austrian army had left the siege of Genoa to reach the Alps. So, the decision was taken to attack immediately. The forces involved amounted to 32 French battalions against 13 allied. The French troops were divided into three attacking columns and their movements began at about 16:30 pm. Despite the desperate effort of the soldiers and the personal value of the French officers, all the attacks were repulsed with heavy losses. In a matter of three hours of murderous firefight, five thousand soldiers, out of 27,000 men engaged, were killed, wounded or missing: even the French commander, the Chevalier de Belle-Isle, was killed in the struggle.Since that day, the Battle of Assietta became a sort of military legend for the Sardinian forces, and subsequently for the Italian Army, but no serious attempt to reconstruct the event was ever made. Only the French at the end of the 19th century tried to develop a more detailed study of the struggle by publishing the manuscript written by the Lieutenant-Général de Vault in the second half of 18th century. This is therefore the first full work to address the history of this battle.