Francia, also called the Kingdom of the Franks, was the largest post-Roman barbarian kingdom in Western Europe. It was ruled by the Franks during Late Antiquity and the Early Middle Ages. After the Treaty of Verdun in 843, West Francia became the predecessor of France, and East Francia became that of Germany. Francia was among the last surviving Germanic kingdoms from the Migration Period era before its partition in 843.

The core Frankish territories inside the former Western Roman Empire were close to the Rhine and Maas rivers in the north. After a period where small kingdoms interacted with the remaining Gallo-Roman institutions to their south, a single kingdom uniting them was founded by Clovis I who was crowned King of the Franks in 496. His dynasty, the Merovingian dynasty, was eventually replaced by the Carolingian dynasty. Under the nearly continuous campaigns of Pepin of Herstal, Charles Martel, Pepin the Short, Charlemagne, and Louis the Pious—father, son, grandson, great-grandson and great-great-grandson—the greatest expansion of the Frankish empire was secured by the early 9th century, and was by this point dubbed the Carolingian Empire.

During the Merovingian and Carolingian dynasties the Frankish realm was one large kingdom polity subdivided into several smaller kingdoms, often effectively independent. The geography and number of subkingdoms varied over time, but a basic split between eastern and western domains persisted. The eastern kingdom was initially called Austrasia, centred on the Rhine and Meuse, and expanding eastwards into central Europe. Following the Treaty of Verdun in 843, the Frankish Realm was divided into three separate kingdoms: West Francia, Middle Francia and East Francia. In 870, Middle Francia was partitioned again, with most of its territory being divided among West and East Francia, which would hence form the nuclei of the future Kingdom of France and the Holy Roman Empire respectively, with West Francia (France) eventually retaining the choronym.