Susa Valley in the context of "Dora Riparia"

Turin (/tjʊəˈrɪn, ˈtjʊərɪn/ ture-IN, TURE-in, Piedmontese: [tyˈriŋ] ; Italian: Torino [toˈriːno] ; Latin: Augusta Taurinorum, then Taurinum) is a city and an important business and cultural centre in northern Italy. It is the capital city of the Piedmont region and of the Metropolitan City of Turin. From 1861 to 1865, it was the first capital of the Kingdom of Italy. The city is mainly on the western bank of the River Po, below its Susa Valley, and is surrounded by the western Alpine arch and Superga hill. The population of the city proper is 856,745 as of 2025, while the population of the urban area is estimated by Eurostat to be 1.7 million inhabitants. The Turin metropolitan area is estimated by the OECD to have a population of 2.2 million.

The city was historically a major European political centre. From 1563, it was the capital of the Duchy of Savoy, then of the Kingdom of Sardinia ruled by the House of Savoy, and the first capital of the Kingdom of Italy from 1861 to 1865. Turin is sometimes called "the cradle of Italian liberty" for having been the political and intellectual centre of the Risorgimento that led to the unification of Italy, as well as the birthplace of notable individuals who contributed to it, such as Camillo Benso, Count of Cavour.

The Turin metropolitan area is the urban agglomeration centred on the city of Turin in the Piedmont region of north-west Italy. It is defined statistically and does not correspond to a single area of local government. Administratively it comprises the comune (municipality) of Turin plus 53 further communes, all of which fall within the Metropolitan City of Turin.

The metropolitan area has a total population of 1,646,064 estimated by the OECD and an area of 1,127 km, giving a density of 1,461 people per square kilometre. It is the fourth most populous metropolitan area in Italy. 51% of the population lives within the city of Turin.

Susa (Latin: Secusia; Segusio, Arpitan: Suisa, French: Suse) is a town and comune in the Metropolitan City of Turin, Piedmont, Italy. In the middle of Susa Valley, it is situated on at the confluence of the Cenischia with the Dora Riparia, a tributary of the Po River, at the foot of the Cottian Alps, 51 km (32 mi) west of Turin.

The March or Marquisate of Turin was a territory of medieval Italy from the mid-10th century, when it was established as the Arduinic March (Latin: marca Arduinica). It comprised several counties in Piedmont, including the counties of Turin, Auriate, Albenga and, probably, Ventimiglia. The confines of the march thus stretched across the Po Valley from the Western Alps in the north, to the Ligurian Sea.

Because of the later importance of the city and valley of Susa to the House of Savoy, whose members styled themselves as "marquises of Susa", the march is sometimes referred to as the March or Marquisate of Susa. Yet in the tenth and early eleventh centuries, the city and valley of Susa were not the most important part of the county, let alone the march, of Turin. Successive members of the Arduinici dynasty were documented far more frequently in their capital, the city of Turin, than anywhere else, and until the late 1020s, Susa was controlled by a cadet branch of the dynasty, rather than by the marquises themselves.