Siege of Pavia (773–74) in the context of Regnum Italicum

The Kingdom of Italy (Latin: Regnum Italiae or Regnum Italicum; Italian: Regno d'Italia; German: Königreich Italien), also called Imperial Italy (Italian: Italia Imperiale; German: Reichsitalien), was one of the constituent kingdoms of the Holy Roman Empire, along with the kingdoms of Germany, Bohemia, and Burgundy. It originally comprised large parts of northern and central Italy. Its original capital was Pavia until the 11th century.

Following the fall of the Western Roman Empire in 476 and the brief rule of Odoacer, Italy was ruled by the Ostrogoths and later the Lombards. In 773, Charlemagne, the king of the Franks, crossed the Alps and invaded the Lombard kingdom, which encompassed all of Italy except the Duchy of Rome, the Republic of Venice and the Byzantine possessions in the south. In June 774, the kingdom collapsed and the Franks became masters of northern Italy. The southern areas remained under Lombard control, as the Duchy of Benevento was changed into the independent Principality of Benevento. Charlemagne called himself king of the Lombards and in 800 was crowned emperor in Rome. Members of the Carolingian dynasty continued to rule Italy until the deposition of Charles the Fat in 887, after which they once briefly regained the throne in 894–896.