PIEDMONT (Italian, Piemonte ; Low Latin, Pedemons and Pedemantiuni), a region of northern Italy, bounded N. by Switzerland, W. by France, S. by Liguria, and E. by Lombardy. Physically it may be briefly described as the upper gathering-ground and valley of the river Po, enclosed on all sides except towards the Lombard plain by the vast semicircle of the Pennine, Graian, Cottian, Maritime, and Ligurian Alps. In 1859 it was divided into the four provinces of Alessandria, Cuneo, Novara, and Torino (Turin), which still remain as provinces of the kingdom of Italy. In 1858 its population was 2,738,814.

The name of Lombardy was used as inclusive of the upper valley of the Po as late as 1091, when the house of Savoy lost most of its Italian possessions by the death of Adelaide; but in the time of Thomas I. (1177-1233), duke of Savoy, while the name Savoy was applied more especially to the ducal territory on the French side of the Alps, that of Piedmont came into use as a collective term for the territory on the Italian side. Thomas II. of Savoy, count (not Thomas II., count of Savoy, as he is often wrongly called), son of Thomas I., obtained (1255) part of Piedmont as an apanage from his brother Amadeus IV., and was appointed imperial vicar in Piedmont by Frederick II.; and, though he was afterwards obliged to renounce all the concessions he had received alike from pope and emperor, his son Thomas III. became the founder of the line which bore the title “Princes of Achaia and Morea, and lords of Piedmont.” Louis, the last of these lords, dying in 1418, left his possessions to Amadeus VIII.