Gaius Cassius Longinus

Gaius Cassius Longinus (86 BC – 3 October 42 BC) was a Roman senator and general, most famous as the main instigator of the conspiracy that killed Julius Caesar on 15 March 44 BC. He was also the brother-in-law of Brutus, another key conspirator. Alongside Brutus, he led troops at the Battle of Philippi against Mark Antony and Octavius, Caesar’s former allies, and took his own life after losing to Antony.

Cassius came from the ancient gens Cassia, a family prominent since the 6th century BC. Little is known about his childhood, except a story that he clashed with the son of the dictator Sulla at school, showing an early dislike of tyrants. He studied philosophy under Archelaus of Rhodes and became fluent in Greek. He married Junia Tertia, daughter of Servilia and half-sister of Brutus; they had one son born around 60 BC.

In 54 BC, Cassius served as quaestor under Marcus Licinius Crassus during the eastern campaign against Parthia. After the disastrous Roman defeat at Carrhae in 53 BC, Cassius led the survivors back to Syria and organized an effective defense. According to Plutarch, Crassus could have avoided the disaster by following Cassius’s advice not to invade. Dio records that both the soldiers and Crassus wanted to give Cassius overall command after the initial defeat, but he refused. In 51 BC, Cassius ambushed and defeated a Parthian army led by prince Pacorus and general Osaces. He initially refused battle, keeping his army inside Antioch. When the Parthians abandoned the siege and began ravaging the countryside, Cassius followed and harassed them. On 7 October, as the Parthians retreated from Antigonea, Cassius’s forces faked a retreat, lured them into an ambush, and surrounded them. Osaces died of wounds, and the Parthians fled back across the Euphrates.

Cassius returned to Rome in 50 BC as civil war loomed between Caesar and Pompey. Elected tribune of the plebs for 49 BC, he sided with the Optimates, though his brother Lucius supported Caesar. After Caesar crossed the Rubicon, Cassius left Italy and joined Pompey in Greece, where he was given command of part of the fleet. In 48 BC, he sailed to Sicily, burning much of Caesar’s navy, then harassed ships off Italy. News of Pompey’s defeat at Pharsalus led Cassius to head for the Hellespont, hoping to ally with King Pharnaces II of Pontus. Caesar overtook him en route, and Cassius surrendered unconditionally.

Caesar made Cassius a legate and employed him in the Alexandrian War against Pharnaces, but Cassius refused to fight against Cato and Scipio in Africa, instead retiring to Rome. Over the next two years, he held office and strengthened his friendship with Cicero. In 44 BC, he became praetor peregrinus, with a promise of the Syrian province the following year. He was deeply offended that his junior and brother-in-law, Brutus, was appointed praetor urbanus.

Though Cassius was the driving force behind the plot against Caesar, winning over the other assassins to the cause of tyrannicide, Brutus became their leader. On the Ides of March, 44 BC, Cassius urged on his fellow conspirators and struck Caesar in the chest. After the assassination, Mark Antony seized power and turned public opinion against them. Cicero’s letters from 44 BC frequently complain that Rome remained under tyranny because the “Liberators” had not killed Antony. Some accounts say Cassius wanted to kill Antony at the same time as Caesar, but Brutus talked him out of it.

After Caesar’s death, Cassius fled east to Syria, where he raised an army of twelve legions. The Senate supported him and made him governor. Later, he and Brutus marched west against the allies of the Second Triumvirate. At Philippi, Cassius was defeated by Mark Antony and died by suicide.

Cassius followed the teachings of the philosopher Epicurus, though scholars debate whether these beliefs influenced his politics. He appears as a main character in Shakespeare’s play *Julius Caesar*, which depicts the assassination and its aftermath. In Dante’s *Inferno*, he is placed in the lowest circle of Hell for betraying and killing Caesar.