The origins of Ortona are uncertain. Presumably, it was first inhabited by the Frentani, an Italic population. In 2005, during works near the Castle, a Bronze Age settlement was discovered, and the Roman town largely coincided with this first settlement. Some sections of paved roads and urban walls, as well as some archaeological findings are the only remains of this period. Ortona remained a part of the Roman Empire i.e., the Byzantine Empire for several centuries, before it was annexed by the Kingdom of the Lombards. In 803 the Franks incorporated Ortona into the county of Chieti. From that date on, the town remained tied to Chieti and its territory.