These settlements served as strategic frontier outposts at the north-east corner of the Italian peninsula, intended to protect the Veneti, allies of Rome at that time.

In the next centuries the Roman roads of Via Postumia, Via Popilia, Via Gemina and Via Annia would link the area to the rest of the Italian peninsula and beyond.

The Roman inhabitants fled en masse to the lagoons, in Veneti and so laid the foundations of the city of Venice.

However, in the 10th century, the Friuli area would suffer under the raids of the Magyars, which would contribute to the decline of imperial control and increase the authority of the patriarchs.

In the 14th century the Patriarchal State known as the Patria del Friuli reached its largest extension, stretching from the Piave river to the Julian Alps and northern Istria.

In December an Imperial army captured Udine; in 1419 the Venetians conquered Cividale; and, then Gemona, San Daniele, Venzone and Tolmezzo followed.

The harvesting of timber needed to build Venetian ships caused complete deforestation of the lower and central Friuli.

[5] In another circumstance Campolongo was put on fire and according to the chronicle of the town leaders (catapano), the priest was killed, the parsonage burned and grains and livestock were removed from the country.

The Ethnographic map of Karl von Czoernig-Czernhausen, issued by the Imperial Administration of Statistics in 1855, recorded a total of over 400 thousand Friulians living in the Austrian Empire.

Around 1825, the province was reorganized into two subdivisions: 1) Istria and 2) Gorizia (includes Campolongo) with Trieste and its immediate surroundings under the direct control of the crown and separate from the local administrative structure.