Caesar’s crossing of the Rubicon
The First Triumvirate worked well initially. Pompey got his legislation through the Senate, Caesar got his consulship in 59 BC and command in Gaul soon after, and Crassus got… well more money. But things rapidly started going downhill when Crassus got himself killed by the Parthians in 53 BC. While Caesar was away campaigning in the North, the kind of one-on-one rivalries the third man was meant to keep in check (“three’s a crowd”) broke out between Caesar, the hard done by general, and Pompey, the Senate’s champion.
The Senate’s problem with Caesar was by now a familiar one. He’d exponentially expanded Roman territory, conquering Gaul and even making it across the famed channel to the mystical land of Britain. Senators worried the extent of his exploits would all go to his head so, deciding to cut him down to size, they decided to prosecute him once his consulship was up over the illegality of his war (in particular the genocide he had committed). Quite understandably Caesar didn’t want to be prosecuted upon his return. Problematically for the Senate, he had several legions at his disposal to protect him from being so.
Backed into a corner, Caesar took a leaf out of Sulla’s book and decided to march on Rome. In 49 BC he crossed the Rubicon, the demarcation where he should have disbanded his army. We now have next to no idea where the River Rubicon would have been. Caesar is often credited with saying “the die is cast” (alea iecta est) as he crossed, suggesting that he realised he’d crossed the point of no return in marching to civil war. This is actually a mistranslation. What he was really saying was, “well I’ve thrown the dice now, let’s hope I’m lucky.”
As chance would have it, he was. Days before Caesar’s arrival Pompey fled Rome with various senatorial colleagues to set up base in Greece. Caesar consolidated power in Rome before pursuing his rival. The two fought all over the Empire, but the decisive battle came at Pharsalus, Greece, in 48 BC. Pompey’s army were routed, and Pompey fled to Egypt where he met a particularly nasty end.
Upon his arrival, Pompey was decapitated on the beach by an old comrade, Lucius Septimius. He was working under the orders of the Pharaoh Ptolemy XIII who was trying to ingratiate themselves with Caesar. It failed. When Caesar arrived in Alexandria later that year and received Pompey’s head as a gift he had Septimius executed and installed a new ruler in Egypt, Cleopatra. Caesar would then spend the next three years until 45 BC campaigning on and off, mopping up the remnants of the senatorial resistance.