49 BC
Julius Caesar crosses the Rubicon
In the last days of the Roman republic, politics had degenerated into a series of struggles between the armies of various politicians of the senatorial rank. Civil war had been waged on and off for decades when three faction leaders agreed on kind of a truce known as the First Triumvirate in 60 BC. To keep their rivalries at a safe distance from Rome, Julius Caesar was alloted Gaul for his ambitions, Pompey was given Spain, and Crassus the Middle East. In 53 BC, Crassus died in battle against the Persians, leaving Caesar and Pompey to maneuver against each other. While Caesar was completing a genocidal conquest of Gaul, Pompey was securing his position in the capital; in 50 BC the Senate, at Pompey’s direction, summoned Caesar home.
Fearing a rigged trial, Caesar decided to come back, but with his army. It was illegal for him to cross the border into Italy, the Rubicon River, with such a force but on this day in 49 BC he did so, at the head of the XIIIth Legion. As he crossed the Rubicon, he is said to have remarked, Alea iacta est, “the die is cast.” Caesar’s invasion forced Pompey to flee but Caesar followed and defeated him at the Battle of Pharsalus, paving the way for his dictatorship, and, eventually, his own assassination.