Of
Volscan origin, after the fall of the
Western Roman Empire Isola del Liri was ruled by the Byzantines and then the
Lombards. In the early Middle Ages the town was, alternatively, under the rule of the
Byzantines and the
Lombards, until it became part of the county of Sora in the
Principality of Capua. Isola del Liri was the feud of the dell'Isola (de Insulae) family from the 12th century to the 14th century. Members of the family include Roffredo dell'Isola, Abbot of Monte Cassino, Count d'Arce, and Bartholomew dell'Isola who enjoyed the honors in the seat of Capuano Naples. At the end of the 14th century, Isola del Liri was ceded to the Cantelmo family. Later it was part of the
Duchy of Sora, becoming a ducal seat under the
Boncompagni family. In 1796 it was annexed to the
Papal States. It was once in the old
Terra di Lavoro region of
Campania, but was transferred to the Lazio during the Fascist period. ==Main sights==