Rubicon (ancient world)
The Rubicon is a small river located in eastern Italy, near the town of Rimini, which historically served as a significant boundary between Italy and Cisalpine Gaul during Roman Republican times. The river gained notoriety in 49 BC when Julius Caesar crossed it with his army, an act that initiated a civil war against Pompey the Great. This crossing represented a pivotal moment, as it was deemed unconstitutional and illegal, marking Caesar's unauthorized entry into his homeland with armed forces. Prior to the crossing, Caesar performed a religious ritual by releasing horses to quell fears of sacrilege, which underscored the tension surrounding his actions. Following the crossing, Caesar quickly advanced southward, prompting his adversaries to abandon Rome and Italy. The phrase "crossing the Rubicon" has since entered common parlance, symbolizing a point of no return in various contexts. The river holds a significant place in the history of Roman politics and military strategy, reflecting the complex dynamics of power during that era.
Subject Terms
Rubicon (ancient world)
Rubico (Fiumicino), River
![Rubicon River flowing through cataract to Hell Hole Reservoir By Marcia Wright (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons 103254823-105458.jpg](https://imageserver.ebscohost.com/img/embimages/ers/sp/embedded/103254823-105458.jpg?ephost1=dGJyMNHX8kSepq84xNvgOLCmsE2epq5Srqa4SK6WxWXS)

A small stream in eastern Italy (Romagna)—a little to the north of Ariminum (Rimini)—forming the boundary, in Roman Republican times, between Italy and Cisalpine Gaul. The civil war between Julius Caesar and Pompey the Great was launched by Caesar in 49 BC when he and his army crossed the Rubicon, since this departure outside Cisalpine Gaul (which formed part of the appointed territory of his governorship), in order to effect an unauthorized entry into the homeland with an armed force, was an unconstitutional and illegal act. After horses had been set free as a religious offering—so as to dispel fears of sacrilege—Caesar sent the only legion he had at his disposal across the stream, and, after himself crossing over with his staff, divided this force into two columns that rapidly moved southward, thus inducing his enemies to evacuate Rome (and subsequently Italy).