The phrase " crossing the Rubicon " is an idiom meaning "passing the point of no return" or, for making irrevocable decisions or embarking on significant new paths. The event known as Julius Caesar's crossing of the Rubicon occurred on 10 January, 49 BC, and marked a pivotal moment in Roman history.
At this time, he was a prominent general and statesman who had expanded Roman territories through military campaigns in Gaul and beyond. The Rubicon River served as a legal boundary and crossing it with an army was considered an act of insurrection against the Roman Senate, which had forbidden him from entering Italy with his legions. This river was one of the two rivers that marked the boundary between the Roman province of Cisalpine Gaul to the north and areas controlled directly by Rome to the south. This bold move ignited a civil war against his rival, Pompey.
Alea iacta est (The die is cast) is another Latin phrase attributed to Julius Caesar by Suetonius on 10 January, 49 BC as he crossed the Rubicon. Caesar probably borrowed the phrase from Menander, the famous Greek writer of comedies. Caesar declared in Greek with a loud voice to all those who were present " Let a die be cast" and led the army across.
Following his crossing, Caesar quickly took control of Rome and the wider Italian peninsula, eventually pursuing Pompey to Egypt, where he was assassinated. Caesar's consolidation of power marked a transition from the Roman Republic to the Roman Empire, as he began to adopt titles and roles that defied traditional republican norms. His reign culminated in his appointment as dictator for life, a position that attracted admiration and resentment, leading to his assassination on 15 March, 44 BC, which ended his dramatic rise and significantly impacted the course of Roman history.
"Crossing of Rubicon coin" refers to a Roman silver Denari struck by Julius Caesar around 49-48 BC, notably the iconic "elephant denarius" minted to fund his army as he famously crossed the Rubicon River.
