Tortona Cathedral

The Diocese of Tortona (Latin: Dioecesis Derthonensis) is a Latin Church ecclesiastical territory or diocese of the Catholic Church in Northern Italy, spanning parts of three regions of Piedmont (Province of Alessandria), Lombardy (Province of Pavia) and Liguria (Province of Genoa). It is a suffragan diocese in the ecclesiastical province of the metropolitan Archdiocese of Genoa and forms part of the ecclesiastical region of Liguria. The diocese claims to be one of the oldest in Lombardy and the Piedmont.

The siege of Tortona in 1155 was the first major military engagement resulting from Holy Roman Emperor Frederick Barbarossa's ambition to enforce Imperial hegemony in Italy.

Tortona (Italian: [torˈtoːna]; Piedmontese: Torton-a [tʊrˈtʊŋa], locally [tʊrˈtɔŋa]; Latin: Dhertona) is a comune of Piemonte, in the Province of Alessandria, Italy. Tortona is sited on the right bank of the Scrivia between the plain of Marengo and the foothills of the Ligurian Apennines. Its frazione of Vho is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy").

Viguzzolo is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 100 kilometres (62 mi) east of Turin and about 25 kilometres (16 mi) east of Alessandria. As of 31 December 2004, it had a population of 2,964 and an area of 18.3 square kilometres (7.1 sq mi).Viguzzolo borders the following municipalities: Berzano di Tortona, Casalnoceto, Castellar Guidobono, Pontecurone, Sarezzano, Tortona, and Volpeglino.

Sarezzano (Western Lombard: Sarsòu) is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 100 kilometres (62 mi) east of Turin and about 25 kilometres (16 mi) east of Alessandria. As of 31 December 2004, it had a population of 1,171 and an area of 13.8 square kilometres (5.3 sq mi).The municipality of Sarezzano contains the frazioni (subdivisions, mainly villages and hamlets) Baracca, Cucco, Palazzina, Rocca Grue, San Ruffino, and Sant'Innocenzo. Sarezzano borders the following municipalities: Berzano di Tortona, Cerreto Grue, Monleale, Montegioco, Tortona, Viguzzolo, and Villaromagnano.

Villaromagnano is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 100 kilometres (62 mi) southeast of Turin and about 25 kilometres (16 mi) southeast of Alessandria. Villaromagnano borders the following municipalities: Carbonara Scrivia, Cerreto Grue, Costa Vescovato, Paderna, Sarezzano, Spineto Scrivia, and Tortona.

Castellar Guidobono is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 100 kilometres (62 mi) east of Turin and about 25 kilometres (16 mi) east of Alessandria. Castellar Guidobono borders the following municipalities: Casalnoceto, Viguzzolo, and Volpeglino.

Castelnuovo Scrivia is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 90 kilometres (56 mi) east of Turin and about 20 kilometres (12 mi) northeast of Alessandria.

Pontecurone (Piedmontese: Poncròu) is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located on the left bank of the Curone, about 100 kilometres (62 mi) east of Turin and about 25 kilometres (16 mi) east of Alessandria. Pontecurone borders the following municipalities: Casalnoceto, Casei Gerola, Castelnuovo Scrivia, Rivanazzano Terme, Tortona, Viguzzolo, and Voghera. In 1635 it was the site of a battle in which Odoardo Farnese, duke of Parma and Piacenza and allied to the French, defeated the Spanish troops under Caspar Azevedo.

Villalvernia is a comune, population 932, in the Province of Alessandria in Piedmont, Italy, situated in a hilly area on the right bank of the Scrivia.

The Grue is a torrent in north-west Italy, a right tributary of the Scrivia, whose 32-kilometre (20 mi) course lies entirely within the Province of Alessandria, Piedmont. The river’s source is at Bocchetta del Barillaro, at an elevation of 636 metres (2,087 ft) close to the watershed with the Val Borbera. The river follows a tortuous course through the Ligurian Apennines, and between the hills of Tortona, before entering the Po plain at Viguzzolo. From here its path is straighter and it debouches into the Scrivia near Castelnuovo Scrivia at 85 metres (279 ft) above sea level. The communes through whose territory the Grue passes are Dernice, Garbagna, Avolasca, Casasco, Montemarzino, Montegioco, Cerreto Grue, Sarezzano, Viguzzolo, Berzano di Tortona, Tortona, and Castelnuovo Scrivia.

Paderna is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about 100 kilometres (62 mi) southeast of Turin and about 25 kilometres (16 mi) southeast of Alessandria. Paderna borders the following municipalities: Carezzano, Costa Vescovato, Spineto Scrivia, Tortona, and Villaromagnano.