Rubicon - Location Confusion and Resolution

Location Confusion and Resolution

After Caesar's crossing, the Rubicon was a geographical feature of note until Emperor Augustus abolished the Province of Gallia Cisalpina (today’s northern Italy) and the river ceased to be the extreme border line of Italy. The decision robbed the Rubicon of its importance, and the name gradually disappeared from the local toponymy.

After the fall of the Roman Empire, and during the first centuries of the Middle Ages, the coastal plain between Ravenna and Rimini was flooded many times. The Rubicon, as with other small rivers of the region, often changed its course during this period. For this reason, and to supply fields with water after the revival of agriculture in the late Middle Ages, during the 14th and 15th centuries, hydraulic works were built to prevent other floods and to regulate streams. As a result of this work, these rivers eventually started flowing in straight courses, as they do today.

With the revival of interest in the topography of ancient Roman Italy during the 15th century, the matter of identifying the Rubicon in the contemporary landscape became a topic of debate among Renaissance humanists. To support the claim of the Pisciatello, a spurious inscription forbidding the passage of an army in the name of the Roman people and Senate, the so-called Sanctio, was placed by a bridge on that river. The Quattrocento humanist Flavio Biondo was taken in by it; the actual inscription is conserved in the Museo Archeologico, Cesena. As the centuries went by, several rivers of Italian Adriatic coast between Ravenna and Rimini have at times been said to correspond to the ancient Rubicon.

The Via Aemilia (National Road №9) still follows its original Roman course as it runs between hills and plain; it would have been the obvious course to follow as it was the only major Roman road east of the Apennine Mountains leading to and from the Po Valley. Attempts to deduce the original flow of the Rubicon can be done only by studying written documents and other archaeological evidence such as Roman milestones, which indicate the distance between the ancient river and the nearest Roman towns.

It is important to underline that the starting point of a Roman road (some kind of “mile zero”), from which distances were counted, was always the crossing between the Cardo and the Decumanus, the two principal streets in every Roman town, running north-south and east-west, respectively. In a section of the Tabula Peutingeriana, an ancient document showing the network of Roman roads, a river in north-eastern Italy labeled “fl. Rubicū” is marked at a position 12 Roman miles (18 km) north of Rimini along the coastline; 18 km is the distance between Rimini and a place called “Ad Confluentes”, drawn west of the Rubicon, on the Via Aemilia.

In 1933, after various efforts spanning centuries, the river now called Fiumicino, crossing the town of Savignano di Romagna (now Savignano sul Rubicone), was officially identified as the former Rubicon. The final proof confirming this theory came only in 1991, when three Italian scholars (Pignotti, Ravagli, and Donati), after a comparison between the Tabula Peutingeriana and other ancient sources (including Cicero), showed that the distance running from Rome to the Rubicon river was 320 km. Key elements of their work are:

• The locality of San Giovanni in Compito (now a western quarter of Savignano) has to be identified with the old Ad Confluentes (“compito” means confluence of roads and it is synonymous with “confluentes”)
• The distance between Ad Confluentes and Rome, according to the Tabula Peutingeriana, is 320 km
• The distance from today’s San Giovanni in Compito and the Fiumicino river is 1 Roman mile (1.48 km)