In 56 BC, at Lucca in Transalpine Gaul, Caesar, Pompey and Crassus formed an informal pact, the “First Triumvirate”. Pompey and Crassus would stand for election as co-Consuls, their second co-Consulship; and each of the three members’ provincial commands would be extended an additional five years – Caesar in Gaul; Pompey in Spain; and Crassus in Syria. This alliance was not intended to protect the Republic’s governing principles; it was not an alliance to promote political, economic or social reform; rather it was an alliance of convenience among highly ambitious rivals. All three wanted to increase their wealth and enhance their military laurels through extended provincial commands.
Pompey and Crassus had served as co-Consuls before. Pompey, considered Rome’s greatest general, had conquered Asia Minor; had defeated the pirates disrupting Italy’s trade routes; and had joined his legions with Sulla in his march to Rome. Crassus had defeated Cinna at the city wall, salvaging Sulla’s assault of the city; and had defeated Spartacus’ massive slave revolt. Caesar had crowned his political resume, rising to Consul, and was in the midst of a long, spectacular campaign to subjugate all of Gaul.
Due to extreme violence and intimidation, the election was delayed, and in January 55 BC, Pompey and Crassus were elected co-Consuls; and, per agreement, each member of the triumvirate was assigned their extended provincial command for five years. Caesar remained in Gaul and continued his military campaign there. Crassus departed to Syria, took command of his army there, and was killed in battle against the Parthians in 53 BC. Pompey remained in Italy, staying at his estate outside of Rome, as required by reforms after Sulla, and delegated his command in Spain to subordinates.
In 53 BC, when Clodius was murdered by supporters of Milo, the Senate cancelled the election and appointed Caesar and Pompey to serve as co-Consuls; however, Caesar declined, intent on completing his campaign in Gaul. To avoid anarchy, the Senate provided Pompey special status, appointing him sole Consul, his third, with unique authority to use his army to restore order in Rome and stabilize the government. Milo was tried under protection of Pompey’s legions, convicted, and exiled.
A series of election laws had banned bribery, but had proven ineffective, as provincial governorships continued to provide rich rewards for investors who backed candidates for high public office. In an effort to curtail this corruption, Pompey banned award of provincial commands for five years after the end of a Consulship; and banned provincial governors from running for office for five years after resigning their provincial governor positions and giving up command of their armies. These were sensible responses to major political corruption problems, and the law was supported unanimously by the Tribunes, but then failed in the Senate.
Near the end of the Gallic campaign, Caesar planned his return to Rome to campaign for Consul in 49 BC, ten years after his first consulship, as required by longstanding law and tradition. The reform after Sulla’s assault on the city remained, requiring provincial governors to resign their positions and give up command of their armies prior to returning to Rome and crossing the city’s boundaries. But Pompey’s special status, awarded by the Senate, had exempted him from this restriction, so that he held a unique position with major advantages not shared by the other members of the triumvirate. The death of Crassus in 53 BC made the restriction moot in his case; but highlighted the differential treatment of the two remaining rivals of the triumvirate. Pompey had been appointed Consul, rather than elected, and he held sole authority with emergency powers; he retained his provincial governorship in Spain as well as command of his army, including legions with him in the capital. Pompey’s advantages represented violations of normal law and traditions that Caesar, so far, was respecting.
Caesar’s reputation had begun to exceed Pompey’s own, and distrust of his political opponents, and fear of his military potential, was rising in the Senate. Under the utterly corrupt and violent conditions that had become typical of Consul elections at that time, it was not practical for Caesar to campaign for Consul from outside of Rome, or to campaign in Rome without protection of his army and without access to the wealth derived from his provincial governorship. This inconsistency of treatment would lead directly to the great confrontation between Caesar and Pompey, and there were extensive efforts made to resolve the escalating dispute, reminiscent of the tense dynamics between Sulla and Cinna a generation before. But Caesar could not return to Rome, even to plead his case to the Senate for equal treatment with Pompey. So Caesar pleaded his case by letters to allies and opponents alike, and through his advocates in the Senate. Key Senators worked, with increasing desperation, toward some compromise, with real fear of a repetition of the bloody confrontation between Sulla and Cinna, and its aftermath. Caesar pleaded for a meeting with Pompey outside the city, and Pompey refused. Caesar offered increasing compromises to transfer much of his provincial territory and their legions to Pompey, finally offering to keep just Cisalpine Gaul and one legion for himself, provided he was allowed to campaign for Consul. Pompey accepted this last offer, but was overruled by the Senate which, led by Cato, was determined to obstruct any path to the Consulship for Caesar.
Caesar then sent a letter to the Senate, which was read publicly, and contained a demand that both Pompey and he must both lay down their commands; the letter was perceived as a threat of war. Mistrust led to rumors that Caesar was organizing his legions to march on Rome, and the Senate called on Pompey to organize his forces to protect the city. The civil war was on; and the Senate passed a decree again providing Pompey emergency powers to protect Rome. After warnings, Caesar’s two primary supporters in the Senate, Antony and Cassius, disguised themselves as slaves and were smuggled out of the city for their own safety. After still more failed negotiations, Caesar positioned three legions in Gaul to block Pompey’s legions in Spain; positioned four additional legions in Transalpine Gaul as a reserve; and brought one legion with him to Rimini, just north of the border between the province and Italy, at the river Rubicon. In January 49 BC, he crossed it, immediately becoming a rebel, and marched south for Rome.
With one legion, Caesar marched south along the flat Aegean coast, taking Rimini, Iguvium, Auxinum, Picenum; then, joined by a second legion, Caesar took Cingulum and Asculum without resistance, Roman forces fleeing before him. Caesar continued marching, joined by a third legion, and laid siege to Corfinium, where its commander, learning that Pompey would not reinforce the garrison, secretly planned his own escape; his soldiers arrested him and all three legions surrendered and joined Caesar’s army. Caesar called the 50 Senators there before him, reiterated his plea for fair treatment, and set them free.
Pompey became convinced that Rome could not be defended with his inexperienced legions, and with the route from Spain blocked, moved southeast to Brindisi, where he concentrated his forces and organized embarkation by sea to Greece, where he planned to build a larger army, and then reinvade Italy as Sulla had done. Caesar’s six legions surrounded him there, but Pompey escaped with the bulk of his force. In ten weeks, Caesar had driven the Republic’s own army off the Italian peninsula.
Caesar then shifted direction to Spain, where Pompey had seven legions. Caesar first stopped in Rome, where he called a meeting of the Senate April 1, meeting outside the city, continuing to respect normal law and tradition, and repeated his plea for fairness, asking for emissaries to meet Pompey and reconcile. The meeting was poorly attended and his requests for support were denied. Caesar then raided the Roman treasury by force for funds to support his army, and proceeded to Spain. He sent two legions in advance to Sicily and Sardinia to secure grain supplies for his army and for Rome; he despatched his three legions in southern Gaul to secure Narbo (Narbonne) and the passes through the Pyrenees; then he sent four legions in Transalpine Gaul across the Alps to secure the critical port of Masilla (Marseilles), which resisted. Caesar left one legion to lay seige to Massilla, and pressed on with his six legions across the Pyrenees, arriving at Ilerda, where he built two bridges across the River Sicorius, and made camp on its west bank. Caesar confronted the Pompeyan forces; first losing an encounter to take a strategic high hilltop; but then prevailing in an effort to secure a pass through the hills behind the Pompeyan forces, closing off their escape route, and then cutting off their water supply. The Pompeiians soon surrendered, were disarmed, and allowed to go free. Pompey’s Spanish allies in western Spain also surrendered, and Massilla was taken after a siege shortly afterward. Italy, Gaul and Spain had been secured by Caesar’s rebel army ten months after it crossed the Rubicon with only one legion.
In 48 BC, the Senate appointed Caesar temporary authority to oversee the election, and he won his second term as Consul. Caesar appointed one of his Commanders, Marc Antony, as his subordinate, and immediately organized his twelve legions and marched to Brindisi. He seized the merchant fleet, built additional transport, and, protected by twelve warships, crossed seven legions across the Aegean, through Pompeiian naval battleship screens; one ship was captured and all aboard were executed. Caesar’s remaining force disembarked in Epirus (Albania) to confront Pompey’s nine legions. Caesar quickly seized the towns of Oricum and Appolonia, their population refused to fight, and the Pompeian forces fled.
A strong beachhead had been secured; Caesar marched north to the port of Dyrrhachium for needed grain supplies, and was cut off by Pompey’s legions, while his 500 ship navy blockaded the beachhead, preventing Caesar’s reinforcements and provisions from Italy, while his legions trapped Caesar’s force on the beach. Caesar again offered a compromise, for the two armies to be disbanded, and for the Roman Senate to meet, debate, and resolve the dispute; these entreaties were ignored by Pompey. Finally, Mark Antony managed to land four additional legions north of Pompey’s army, and Caesar’s combined forces closed around Pompey’s legions at the port. Pompey constructed a 15 mile fortified trench works around the city’s bay, protecting his supply by sea; Caesar responded by constructing a 19 mile fortified trench around Pompey’s, then cut off his fresh water supplies. Pompey identified, attacked and held a gap in the fortified southern terminus of Caesar’s seige line, providing an escape route for his troops and cavalry. Caesar withdrew his forces from the failed siege, and marched southeast to Greece to regroup.
Pompey followed Caesar at a distance, and the armies met on the plain of Pharsalus, in northern Greece, along the River Enipeus. The two armies faced each other in typical formation, Caesar’s 22,000 troops and 1,000 cavalry outnumbered by Pompey’s 45,000 troops and 6,400 cavalry. Caesar’s troops charged the Pompeiian line, while Pompey’s cavalry charged Caesar’s right wing, were met by cavalry and supporting foot soldiers with javelins, and driven back. Caesar’s troops advanced and prevailed against the greater number of Pompey’s force, and defeated it. Pompey stripped his uniform and command insignia and fled to Egypt.
Caesar followed Pompey to Egypt with a small force, meeting a squadron of Pompey’s warships that surrendered on his demand. On Caesar’s arrival in Alexandria, Pompey was assassinated by two of his own former officers, and beheaded. Caesar had entered the Alexandrian civil war between two siblings, heirs to the throne of King Ptolemey XII, intended to be co-rulers of Egypt; these were his youngest son Ptolemy XIII, and his oldest daughter – seventeen year old Cleopatra. Caesar was trapped in the royal palace, surrounded by the army of Ptolomey XII; was reinforced by surrendered Pompeiian forces; and, after several small naval battles in the Royal Harbor, including one where Caesar swam away from a sinking ship, Ptolomey’s forces were defeated. Caesar famously took up with Cleopatra, and sailed the Nile on her royal barge for some months.
In 48 BC, at the end of his second Consulship, Caesar was appointed to a third, again delegating his authority to Mark Antony. Caesar then put down a tribal rebellion in Asia Minor (47 BC); defeated a revolt of Pompeiian forces under Cato aligned with Rome’s old enemy, Numidia, after which Cato committed suicide (46 BC); and defeated a final Pompeiian revolt led by his two sons in southern Spain (45 BC). The Roman Civil war was finally over, and Caesar returned to Rome.