In the Roman Age Friuli did not exist yet: its current territory was indeed included in a much more extended province, ‘Venetia et Histria’, that had its chief city in Aquileia, while ‘Forum Iulii’ was the name of the settlement which had earlier been inhabited by Celts and Paleo-Venetes and was established as market (‘forum’) by Julius Caesar, and accordingly called Forum Iulii, ‘Julius’ market’; it was then raised to a ‘municipium’ ascribed to the Roman tribe Scaptia and lately became the capital of the province after the devastation of Aquileia by Attila in 452. Despite the repeated waves of surging invasions since the beginning of the fifth century, the ancient Roman province still kept, at least formally, its unity when, around the half of the sixth century, Justinian tried to re-establish the imperial authority over these lands. It was due to Lombards, who penetrated in Friuli through the bridge over the Isonzo river (‘pons Sontii’) in 568, that the territorial unity of the old province was definitely split, which brought to the political and administrative conditions for the birth of Friuli. In the most common accepted meaning of the historian of the Lombards, Paul the Deacon [Paolo Diacono], ‘Forum Iulii’ is also called as ‘Foroiuliana civitas’, ‘Foroiuliana urbs’, ‘Foroiulianum’ or ‘Foroiuliense castrum’, ‘Foroiulianum oppidum’. It is however reasonable to hypothesize that beside this meaning, there started to make its way also the perception of a ‘Foroiuliana provincia’ that was headed by the capital city. During the eighth century the name of ‘Friuli’, referred not only to the city, but also to the whole territory of the Lombard duchy is completely affirmed, as evidenced by the contemporary witnesses. The beginning of the history of Friuli are therefore characterized by a duplex aspect with respect to the previous age: on the one hand the break from the past, particularly on the political-institutional level, and an in-depth continuity with respect to the traditions, on the other hand. The split is represented by the invasion in 567 and the establishment of the Lombard duchy. The continuity is, on the contrary, as a deep lymph that uninterruptedly crossed centuries from the Antiquity to the Friulian Middle Ages: first of all the classical and Christian cultural heritage, which was kept and transmitted by the Aquileian Church and the Lombards made their own in the course of time; then the Friulian idiom, a romance language that evidences the persistence of the Latin-Celtic element and of its cultural and religious value with respect to the Germanic inclusions due to Lombards.
In the Roman age the current territory of Friuli, named after ‘Forum Iulii’ (Julius’ market), was included in a much more extended province, ‘Venetia et Histria’, that had its chief city in Aquileia.