Caesar crosses the Rubicon

The story

A small river, a great decision

The Rubicon is a modest river. About 35 kilometres long, it rises in the hills near Sogliano al Rubicone, passes through Savignano sul Rubicone and flows into the Adriatic Sea, a little south of Cesenatico, in the province of Forlì-Cesena, in Romagna. It is a torrent-type river, that is, almost dry in summer and swollen after rain. Yet one night in January 49 BC its name entered history.

To understand why, you need to know that in those days the Rubicon had a very important function. Between 59 and 42 BC it marked the boundary between the Roman province of Cisalpine Gaul and Italy proper, that is, the territory directly tied to the city of Rome. There was a rule: a general could not cross that boundary with his army under arms. The reason was simple: the republic wanted to prevent a general from using his soldiers against the state.

Caesar and the Senate

Gaius Julius Caesar was an ambitious general and politician. For years he had governed Cisalpine Gaul and had conquered Gaul, present-day France, with victories that had made him very famous and rich, and had made his army very loyal. In Rome, however, he had many enemies. Among them was Pompey, another great general, once his ally, and a part of the Senate that feared him.

Between the end of 50 and the first days of 49 BC the Senate ordered him to disband his army, give up the government of the province and return to Rome as a private citizen. Caesar was afraid. He feared being put on trial and losing everything, and he also thought that his supporters, the populares, were in danger. He refused to obey.

The night of the Rubicon

In the early hours of 10 or 11 January 49 BC, according to scholars' reconstruction, Caesar crossed the river at the head of the Thirteenth Legion, the Legio XIII Gemina, with about 5,000 foot soldiers and 300 horsemen. They were not many, but they moved fast. In this way he entered the territory of Italy under arms, and that act was equivalent to declaring war on the Republic. His lieutenant Titus Labienus, who had followed him for years in Gaul, went over instead to the side of Pompey and the Senate. The Senate had only two legions in Italy.

Caesar hesitated, at least according to the ancient authors. Then, they say, he made his decision. The historian Suetonius, who wrote more than a century after the events, reports the phrase in Latin: iacta alea est, which we translate as “the die is cast”. Another author, Plutarch, writes the same phrase in Greek, and says it was a quotation from the playwright Menander. Scholars are cautious: nobody knows whether Caesar really spoke those words, and in which language. It could be a phrase attributed to him afterwards, to give shape to a moment. The humanist Erasmus of Rotterdam thought it should be read as an order: “let the die be cast”. In Latin alea meant the game of dice and, by extension, risk and gamble.

Which river is it?

Not even the river is certain. The ancient Rubicon flowed between Rimini and Cesena, but we do not know whether it is the same as the river that bears the name today. Scholars have proposed other candidates, such as the Pisciatello and the Uso. In the past the river we now call the Rubicon was called the Fiumicino and was officially renamed Rubicone in the 1930s. Many elements, such as the Roman bridge at Savignano and the remains of a military post found near Gatteo, suggest that it is the right one, but the question is still open. According to the tradition, Caesar spoke to his soldiers at Rimini, where a column marks the spot.

After the Rubicon

Once across the river, Caesar advanced rapidly. Pompey and much of the Senate left Rome. A civil war began, that is, a war between citizens of the same state, which would be fought in Italy, in Greece, in Africa and in Spain and would end only with Caesar's victory.

The story of the crossing became so famous that it is still used today as a figure of speech: “to cross the Rubicon” means to make an irrevocable decision, from which there is no turning back. The motto alea iacta est has also become universal and appears, in slightly different forms, on the coats of arms of the town of Rimini and of the province of Forlì-Cesena.