Rubicon

The Rubicon (Rubico; Rubicone rubiˈkoːne; Rubicôn rubiˈkoːŋ) is a shallow river in northeastern Italy, just north of Rimini. It was known as Fiumicino until 1933, when it was identified with the ancient river Rubicon, famously crossed by Julius Caesar in 49 BC. The river flows for around from the Apennine Mountains to the Adriatic Sea through the south of the Emilia-Romagna region, between the towns of Rimini and Cesena. The Latin word Rubico comes from the adjective rubeus, meaning "red". The river was so named because its waters are colored red by iron deposits in the riverbed. During the Roman Republic, the Rubicon marked the boundary between the Roman province of Cisalpine Gaul and Italy proper, controlled directly by Rome and its socii (allies), to the south. On the north-western side, the border was marked by the river Arno, a much wider and more important waterway, which flows westward from the Apennine Mountains (the Arno and the Rubicon rise not far from each other) into the Tyrrhenian Sea. In 49 BC, perhaps on January 10, Julius Caesar led a single legion, Legio XIII Gemina, south over the Rubicon from Cisalpine Gaul to Italy to make his way to Rome. In doing so, he deliberately broke the law limiting his imperium, making armed conflict inevitable. Suetonius depicts Caesar as undecided as he approached the river, and attributes the crossing to a supernatural apparition. It was reported that Caesar dined with Sallust, Hirtius, Gaius Oppius, Lucius Cornelius Balbus, and Servius Sulpicius Rufus on the night after his crossing. According to Suetonius, Caesar uttered the famous phrase alea iacta est ('the die is cast') upon crossing the Rubicon, signifying that his action was irreversible. The phrase "crossing the Rubicon" is now used to refer to committing irrevocably to a grave course of action, similar to the modern phrase "passing the point of no return," but with the added connotation of risking danger. The presence of Caesar and his legion in Italy forced Pompey, the consuls, and a large part of the senate to flee Rome.