Summary
Highlights
The first century BC in Rome was marked by powerful yet destructive figures. The assassination of the Gracchi brothers in the mid-2nd century BC highlighted a growing social divide, fostering instability that led to the civil wars of Sulla and Marius. These conflicts exposed flaws in the Roman Republican system, demonstrating that military power could subvert politics and set a dangerous precedent for generals to march on Rome. The First Triumvirate, comprising Crassus, Pompey, and Caesar, emerged from this environment. Crassus provided wealth, Pompey military prestige, and Caesar populist influence. Their combined power dominated Roman political life for years.
The Triumvirate began to fracture with the death of Caesar's daughter Julia in childbirth in 54 BC, severing the bond between Caesar and Pompey. Crassus's disastrous Parthian campaign and death in 53 BC, followed by the killing of Clodius by Milo, left Pompey and Caesar as the two most powerful men in Rome. The ensuing chaos led the Senate to grant Pompey sole consulship and extraordinary powers in 52 BC. Concerned by Caesar's growing power and loyal legions, key Optimates like Cato the Younger rallied against him, pushing Pompey to lead the opposition. Caesar's request to run for consul in absentia became a point of contention, as denying it would strip him of legal immunity, making him vulnerable to prosecution.
Despite negotiations, the Senate, backed by Pompey, ordered Caesar to resign his command, an order Caesar refused, fearing trial. Tensions escalated, and on January 7th, 49 BC, the Senate passed the 'Senatus Consultum Ultimum', effectively declaring Caesar an enemy of the state and granting Pompey full control. On January 10th, 49 BC, Caesar, with the 13th Legion, crossed the Rubicon River, an act of war. Caesar's swift advance through Northern Italy met little resistance, as many sympathized with him. Pompey, initially indecisive, decided to abandon Rome and Italy, evacuating his forces to Greece. Caesar, unable to pursue by sea, entered Rome, plundered the treasury, and declared Pompey an enemy of the state, before turning his attention to securing his western flank.
Caesar aimed to defeat Pompey's forces in Hispania before confronting Pompey directly. He dispatched lieutenants to Sardinia and Sicily to secure grain supplies, and marched his main force to Spain. Along the way, he laid siege to Massilia, a city vital for the route to Spain, leaving a detachment to continue the siege. In Hispania, Caesar faced Pompey's experienced Legates, Afranius and Petreius, who were positioned strategically at Ilerda. After an initial setback and supply issues caused by a flood, Caesar skillfully used his engineering prowess to establish a new bridge and gain control of the eastern bank of the Sicoris River. This allowed his cavalry to harass Pompeian foragers, turning the tide of the campaign.
Facing dwindling supplies and growing local support for Caesar, Afranius decided to withdraw to Further Spain to merge with Varro’s legions. However, Caesar's persistent pursuit and cavalry harassment slowed their retreat. Caesar managed to cut off the Pompeian escape route to the mountains, trapping them. After a brief period of fraternization between the opposing soldiers and a brutal reassertion of discipline by Petreius, the Pompeians, blockaded and starved, were forced to sue for peace. Caesar offered leniency in exchange for their complete surrender and the promise not to take up arms against him. Varro in Further Spain, seeing the overwhelming support for Caesar, also surrendered his legions without a fight, effectively ending Pompey’s control in Hispania.
While Caesar secured Spain, the protracted siege of Massilia continued. Despite strong defenses, the Massilians' fleet was defeated by Brutus, and innovative Roman siege engineering eventually brought the city to the brink of collapse. A desperate sortie from the Massilians temporarily set back the Roman siege works, but ultimately, disease, starvation, and the return of Caesar's victorious legions forced Massilia's surrender. Around the same time, Caesar’s legate Curio led an invasion of North Africa to secure grain supplies. Initially successful against Varus, Curio was tricked by Juba of Numidia into a pitched battle against a supposedly small force. Curio's exhausted and inexperienced legions were annihilated, with Curio dying in battle. This significant defeat left Africa in Pompeian hands and highlighted the inexperience of some of Caesar's subordinates.
Despite setbacks for his subordinates, Caesar's Spanish campaign was a resounding success, bolstering his army. He swiftly addressed a mutiny in his veteran 9th Legion through a mix of sternness and magnanimity. With Rome lacking consuls, Caesar was named Dictator for 11 days to oversee elections, legitimizing his cause and securing his position as Consul. He then gathered his forces at Brundisium to confront Pompey, who was assembling a massive multi-ethnic army in Greece. Exploiting the misconception that it was winter, Caesar launched a daring sea crossing of the Adriatic, landing 7 legions in Greece before Pompey’s navy could react, effectively trapping himself but taking the initiative.
After landing, Caesar quickly advanced, aiming for Dyrrhachium, a key Pompeian supply center. Pompey, alerted by a captured Caesarean, raced to secure Dyrrhachium, forcing Caesar to retreat to a defensive position on the Apsus River. A prolonged standoff ensued, with Pompey, despite numerical superiority, unwilling to engage Caesar's veterans on unfavorable terms. Caesar harassed Pompey's naval blockade to disrupt supplies and eventually, Mark Antony successfully brought the remaining Caesarean legions across the Adriatic, uniting Caesar's forces. Caesar then began an aggressive strategy to besiege Pompey's main camp at Dyrrhachium, constructing extensive fortifications to encircle Pompey's larger army. This led to frequent skirmishes and a period of intense siege warfare, with both sides constructing elaborate earthworks.
Exploiting intelligence from defectors, Pompey launched a coordinated three-pronged attack on a weakly defended section of Caesar's fortifications near the coast. His men overwhelmed the 9th Legion, breaching Caesar's lines. Despite Antony's swift response and Caesar's arrival with reinforcements, the Caesareans suffered a significant defeat and were forced to retreat. Pompey, fearing a trap, did not pursue further, allowing Caesar's army to escape total annihilation. Though Caesar minimised his losses, it was a clear and costly defeat, breaking his encirclement of Pompey. Hailed as Imperator, Pompey missed an opportunity to deliver a knockout blow. Caesar, regrouping, comfortingly told his men that this defeat would precede a greater victory, mirroring his experience at Gergovia before Alesia.
Following his defeat at Dyrrhachium, Caesar faced a precarious situation with scattered forces. He prioritized uniting his depleted army with Domitius Calvinus's legions in Macedonia. Both Caesar and Pompey raced to reach their respective allies, with Caesar eventually a few hours away. Through a stroke of luck, Gallic defectors warned Domitius of Pompey's approach, allowing him to merge with Caesar's forces. Despite still holding the upper hand in numbers and local support, Pompey chose a Fabian strategy, aiming to wear Caesar down through attrition. However, intense pressure from his officers, eager for a decisive victory, forced Pompey to change his mind. Caesar, demonstrating his veterans' skill by quickly storming Gomphi, continued to resupply his army. Finally, Pompey relented to his officers' demands and marched his army to Pharsalus, prepared for a pitched battle.
At Pharsalus, Pompey's army, significantly outnumbering Caesar's, was confident of victory. Pompey planned to use his superior cavalry to flank Caesar's legions, crushing them like a 'hammer to an anvil', a tactic inspired by Alexander the Great. Caesar, despite being outnumbered, relied on his disciplined veterans. He strategically placed his most experienced legions, including his favorite 10th Legion, and formed a hidden 4th line armed with spears to counter Pompey's cavalry. When Pompey's cavalry attacked, Caesar's 4th line emerged, catching them by surprise and routing them. This decisive maneuver broke Pompey's left flank, and with Caesar committing his reserves, Pompey's lines collapsed. Pompey himself fled to his camp, which Caesar's victorious legions then stormed. Caesar's victory was overwhelming, with most of Pompey's army either killed or surrendering.
While many high-ranking Pompeians, including Labienus and Pompey's sons, escaped, figures like Ahenobarbus were killed. Among the captured was Marcus Junius Brutus, whom Caesar spared due to his personal connection. Caesar, showing his customary leniency, absorbed thousands of Pompey's surrendered soldiers. Pompey, fleeing with a small bodyguard, eventually sailed to Egypt, hoping to find refuge and rebuild his forces with the help of Ptolemy XIII. However, upon arrival, he was betrayed and brutally assassinated by the Egyptian court, who sought to win favor with Caesar. Caesar, on receiving Pompey's head, reacted with disgust and tears, acknowledging the death of a formidable rival and former ally. The Battle of Pharsalus marked a turning point, but the Civil War was not over, with Pompey's staunch supporters continuing the resistance in North Africa.