Julius Caesar’s Civil War with Pompey the Great

The Caesar-Pompey War erupted in 49 BCE, a Roman Republic in serious political crisis. The conflict lasted until 45 BCE and was an event permanently etched in the annals of history. The two brilliant generals, who, with the support of their loyal legions, had achieved great victories beyond the borders of the Republic, decided to oppose each other in a decisive battle for control of the Eternal City.

The political landscape of Republican Rome in the 1st century BCE was extremely fragmented, with centuries-old institutional rules increasingly being violated, and politicians engaging in illegal activities enjoying impunity. Two political parties dominated Rome: the optimates (representing the interests of the aristocracy), led by Gnaeus Pompeius in the mid-1st century BCE; and the populares (advocating for the lower classes), represented by Julius Caesar. Both politicians wielded enormous influence and regularly corrupted other politicians to strengthen their position against their opponents.

As late as 60 BCE, the two politicians, along with the wealthiest Roman – Marcus Crassus – formed the so-called Triumvirate (literally “three men”), an unofficial political alliance that effectively determined the selection of state officials and the fate of the Roman state. It was thanks to this alliance that Pompey consolidated his power in Rome, and Caesar was able to wage brilliant military campaigns in Gaul, Germania, and Britain in the years 58-51 BCE. The agreement was further cemented by the marriage of Caesar’s daughter, Julia, to Pompey.

Unexpectedly, however, news arrived of the death of Caesar’s daughter, Pompey’s wife, which ultimately severed the friendly relations between them. Furthermore, in 53 BCE, Marcus Crassus was killed in a battle with the Parthians at Carrhae (present-day southern Turkey), which ultimately ended the political alliance and increasingly alienated Caesar and Pompey.

The lack of agreement, the growing hostility, and the rivalry for power between the two most ambitious and influential Romans of the time forced them on a collision course. In 50 BCE, Caesar’s mandate as governor of the Gallic provinces was expiring, a fact that the hostile, conservative optimates attempted to exploit. Fearing for his political position and the possibility of being relegated to the rank of an ordinary Roman citizen, Caesar sought to assume the consulship.

Pompey sought at all costs to strip Caesar of his greatest strength – his loyal and experienced legions. To this end, a law was introduced that established a mandatory five-year hiatus between his term in office in Rome and that of governor. Furthermore, to participate in the elections, Caesar had to return to Rome, which would allow him to deal with Caesar politically and in the courts.

Caesar sent his representatives to the Senate, but the Senate ordered them sent back without hearing their views. Caesar exploited this fact to persuade his soldiers to accept a military coup in Rome. Julius Caesar, realizing his hopeless situation and lack of sufficient influence in Rome, decided to take decisive action.

On January 7, 49 BCE, the Senate ordered Julius Caesar to transfer his army to the command of the new governor of Gaul. Caesar learned of this information in Ravenna. On January 10 or 11, 49 BCE, Caesar, at the head of his loyal soldiers, crossed the Rubicon, the river that marked the border between the province of Cisalpine Gaul (Gallia Cisalpina) and Italy, which was under the control of the state. It was then that Caesar uttered the famous words: “Alea iacta est!” (“The die is cast”), which heralded the beginning of the war. The place where Caesar likely crossed the river is the present-day bridge in the city of Savignano in Italy. This is likely where the ancient Via Aemilia passed.

According to Roman law during the Republican period, provincial governors were officials with the power of “imperium” (the right to command an army) within their provinces. Therefore, they could not operate their troops outside their sphere of influence. Roman law allowed only consuls and praetors to administer empire in Italian lands. If a general lacked special authority to enter Italian territory, he or she first had to disband the army. Anyone who disobeyed this law and entered Italy at the head of an army automatically lost empire and command of the army and was sentenced to death. Furthermore, soldiers who maintained their allegiance to their commander without official authority were also subject to the death penalty. Caesar had staked everything on one card.

Caesar’s rapid march and utter surprise caused cities in Italy to fall or open their gates to Caesar’s legionaries. The panic that gripped Rome forced the evacuation of most of the optimates and Caesar’s enemies (including Pompey), who fled to Greece. It was there that they decided to gather forces and confront Caesar’s forces. He, in turn, immediately entered the capital, opened the treasury in Rome, and obtained the funds needed for a further military campaign.

After conquering the Italian Peninsula, Caesar needed to secure the rear of his future operations. To this end, he led his legions to Massalia (present-day Marseilles in southern France), which was hostile to Caesar, and then to Spain, where he defeated the army of Afranius and Petreius, supporters of the Senate, and occupied Farther Spain. However, he did not punish his defeated opponents, but merely ordered their army disbanded.

Upon returning to Rome, in December 49 BCE, Caesar was proclaimed dictator by a cowed Senate and set out against his main enemy in Greece. Knowing he had no naval advantage, Caesar decided to surprise Pompey, who had been in Greece since he took power in Rome. He quickly gathered seven legions and, without a particularly large escort of warships, crossed to what is now Albania. Unfavorable weather conditions and a smaller fleet meant that Caesar had significantly fewer forces on the Balkan Peninsula and faced supply problems. After several months of maneuvers and scouting the enemy, the conqueror of Gaul decided to attempt to defeat Pompey at Dyrrachium in 48 BCE. The significant disparity in Pompey’s forces proved decisive, and Caesar was forced to retreat. Faced with massive losses and supply difficulties, Caesar decided to retreat eastward, toward the approaching army of Quintus Metellus Scipio, who was expected to reinforce Pompey’s forces. Caesar set up camp on a hill above the Enipeus River near Pharsalus. Caesar was constantly trailing Pompey, accused of fearing the Caesarians.

The decisive battle between Caesar and Pompey took place on August 9, 48 BCE, at Pharsalus. There, Pompey’s much larger legions yielded to Caesar’s exceptionally disciplined “war machine,” which forced the enemy to flee. Caesar’s ruse, using several of his cohorts behind his right wing to reduce Pompey’s cavalry advantage, was crucial. The collapse of Pompey’s left flank allowed Caesar’s troops to circumvent it and attack the Pompeian forces from the rear. Panic immediately spread among the enemy troops. Pompey’s infantry began to flee, and was massacred by Caesar’s pursuing troops. Catching up with them in their camp, Caesar announced that he would not punish them, provided that Pompey’s legionaries joined his victorious army. The soldiers accepted his offer with relief. Senior officers, in turn, could also expect to retain their property in exchange for surrendering to Caesar. Caesar demanded only a promise not to join Pompey, while generously rewarding those who chose to change sides. This strategy ultimately caused most senators to defect to Caesar’s camp, and Pompey could no longer claim to be the defender of the Republic and the Senate.

Abandoned by his troops, Pompey decided to flee to Egypt, where he hoped for support from—he believed—his allies. However, to his great surprise, the teenage King Ptolemy XIII, at the urging of his advisors, ordered his execution to curry favor with Caesar. The death of his rival under such circumstances enraged Caesar more than pleased him. The Greek historian Plutarch recounted that Caesar refused to look at his rival’s face, but instead took Pompey’s signet ring and shed tears. Caesar lost his rival for the throne, but Pompey left behind two sons: Gnaeus and Sextus, who were supported by Pompey’s supporters, led by Scipio Metellus and Cato the Younger.

Pompey’s defeat and death did not mean the end of the civil war in Rome. The optimates, grouped around Cato the Younger and Scipio in Africa, continued to resist. Caesar finally defeated them at the Battle of Thapsus in 46 BCE.

After his recent victories, Caesar could finally afford a triumph in Rome itself in the summer of 46 BCE. It was a massive celebration celebrating his victories in Gaul, Egypt, Pontus, and Africa. Several days of feasts, festivities, and tournaments were held, and Caesar himself, to curry favor with the people, generously bestowed spoils of war upon everyone.

After settling matters in Rome, Caesar decided to finally crush the supporters of the late Pompey. In November of 46 BCE, Caesar set out for Spain to finally deal with his only opponents, Pompey’s sons, Sextus Pompeius and Gnaeus Pompeius. The decisive battle took place on March 17, 45 BCE, near Munda, in which Caesar’s army, despite overwhelming odds, defeated the Pompeians.

After the Battle of Munda, no one could challenge Caesar’s sole rule. In 44 BCE, the Senate proclaimed Caesar dictator in perpetuum (dictator in perpetuum), high priest, emperor, and “father of the fatherland.” Attempts were made to proclaim him king of Rome, but Caesar refused, as this position had been hated by the people since the time of the Tarquins; moreover, Caesar continued to strive to maintain a veneer of republican legality.

The optimates were alarmed by Caesar’s unfettered power, which forced them to decide to assassinate the dictator. The opposition to Caesar was led by Gaius Cassius Longinus and Marcus Junius Brutus. They had previously been associated with Pompey’s camp, but after the defeat at Pharsalus, they surrendered to Caesar and received his pardon; however, they continued to proclaim their hostility towards him. On the day of the conspiracy, Caesar almost thwarted the assassins’ plans. His wife begged him to stay home, as she was plagued by bloody nightmares that night. Caesar reluctantly agreed to her request, but the assassins’ envoys, visiting his home, convinced him to attend a Senate meeting.

Ultimately, at a Senate meeting on March 15, 44 BCE, the Ides of March, the conspirators stabbed Caesar to death at the foot of Pompey’s statue. According to Plutarch, Caesar was stabbed a total of 23 times (which would indicate a tight-knit group of conspirators).

As it turned out, Caesar’s death sparked further unrest in Rome and another civil war, in which Caesar’s adopted son, Gaius Octavian, and Caesar’s general and supporter, Mark Antony, played the first cards. Ultimately, Octavian won the struggle against Caesar’s murderers, and later against Mark Antony, and as Emperor Octavian Augustus, he began the rule of the new Julio-Claudian dynasty and established a new political system – the Principate.