The Rubicon River
Although so geographically insignificant that its true location was uncertain for centuries, the Rubicon River, located in northeast Italy, was the site of one of the most pivotal moments in Roman history.
The Rubicon River was eventually correctly identified by scholars and its historical name was restored, acknowledging its role in the transition from the Roman Republic to the Roman Empire.
Geography
The Rubicon runs 50 miles from its source in the Apennine Mountains to its mouth on Italy's east coast, where it empties into the Adriatic Sea. The river is relatively narrow and shallow; today it is better identified as a stream.
The Rubicon crosses Emilia-Romagna's southern region between modern-day Rimini and Cesena. It runs between the Pisciatello River to the north and the Uso River to the south.
Name
The river's name comes from "rubico", a Latin word derived from "rubeus", meaning "red".
In ancient times, the Rubicon's waters were tinted red due to the iron deposits that settled in its bed, which originated from its mountain source.
Historical Significance
The Rubicon river was the natural border used by the Roman Republic to delineate Cisalpine Gaul, a Roman province to the north, and Roman-controlled Italy to the south.
Just like today, rivers were convenient demarcating lines for establishing borders in ancient times, as they were permanent and well-defined.
The Roman Senate and elected consuls controlled Italy during the Republican period. Each outlying province was managed by an appointed governor who oversaw its expansion, rule, and security. These provinces were allowed to exist somewhat autonomously as long as they acknowledged Roman rule and their place in the Republic.
Julius Caesar
Late in the Roman Republic, Julius Caesar was appointed governor of Cisalpine Gaul. He exercised masterful militaristic skill by defeating the Celtic and Germanic tribes throughout Gaul. He also acquired a vast personal fortune and rose as a popular leader with both his army and the masses.
His growing profile was perceived as a threat by both the Senate and Pompey, a rival general and consul.
Beyond leading their province, governors held "imperium" or "the right to command," making them generals of the army stationed in the region. The paid and professional Republican legions were loyal to their generals rather than the Republic. As a result, the law prohibited generals from entering Italy with their armies.
As his term as governor wound to a close, Caesar was legally obligated to return to Rome as a private citizen. Aside from ending his political aspirations - as Caesar was forbidden from running for consul - private citizenship allowed Caesar to be sued for his debts and prosecuted for unauthorized military actions throughout Gaul.
Under Roman law, only elected officials could hold "imperium" within Rome proper. If an appointed governor from a province entered Rome, he had to forfeit command of his troops, otherwise both the general and the members of his legion would be deemed traitors. As a result, governors had to disband their armies before returning home.
Crossing the Rubicon
On 7 January 49 BC, the Roman government formally demanded that Caesar hand over control of his army and transfer his governorship to his successor.
Three days later, Caesar was in Ravenna, near the border, contemplating his next move. Ultimately, he led his XIII Legion across the Rubicon, crossing from Cisalpine Gaul into Italy.
Caesar saw his calculated and intentional violation of Roman law as a necessity. His actions at the Rubicon are considered the spark that ignited the Second Civil War.
Tensions had been building as the political rivalry between Caesar and Pompey had grown for years, making a showdown inevitable. Crossing the Rubicon was the first step in Caesar's rise to power and the establishment of the Roman Empire.
It's unclear exactly where Caesar and his army crossed. However, after crossing, he and his army headed for Rome. Pompey fled south and then to Greece while the Senators dispersed. A five-year civil war followed, ending with Caesar becoming dictator for life.
The Die is Cast
According to the Roman historian Suetonius, who briefly served as Hadrian's secretary, Caesar was contemplative at the time of his crossing. He heavily weighed the choice before resolving to enter Italy and advance to Rome.
Suetonius' position within the government provided access to primary resources and official documents, making his account presumably quite reliable.
Per Suetonius' account, Caesar stated, "Let us go where the omens of the Gods and the crimes of our enemies summon us. The die is now cast." The phrase was likely a reference to Menander, Caesar's favorite poet.
The Idiom
Over time, the phrase "Crossing the Rubicon" has been used to describe a situation in which an individual or group fully commits to a course of action, acknowledging that they cannot turn back, regardless of the potentially dire consequences.
Caesar's decision to cross the river had two only outcomes; his death, or control of Rome.
Rediscovering the Rubicon
The river only maintained its significance until 42 BC when Octavian dissolved the province of Cisalpine Gaul and incorporated it with the rest of Italy. The Rubicon no longer served as a border and, because it was not a significant trade route, was largely forgotten.
In the centuries after the fall of Rome, the river continued flooding and receding across the region. In the Middle Ages, engineers worked to stabilize the river, allowing farming in the area that did not risk being washed away.
Despite being the site of a pivotal moment in human history, the Rubicon's actual location was lost. Scholars debated whether the Pisciatello, Uso or Fiumicino - three rivers in northeastern Italy - were the historical Rubicon. In 1933, historians ascertained Fiumicino was the true historical border and the site of Caesar's crossing.
Although accepted by most historians, the site of the Rubicon remained disputed right up until 1991. Researchers used the Tabula Peutingeriana, a surviving copy of a Roman map from the Middle Ages, to verify the Rubicon based on its 12-mile distance from Arimunum, which is now known as Rimini.
