Help came only when Caesar returned from his governorship in Spain. Pompey, Crassus, and Caesar formed the unofficial and at first secret “First Triumvirate.” (This was not a legal position, and the term, although convenient, is modern.) It was to become more than a mere election compact. It would strain all the resources of the triumvirs to wrest one consulship from the Optimates; their continued solidarity was essential if they were to secure what Caesar gained for them in 59. Caesar, for his part, wanted a long-term command. Pompey, who now married Caesar’s daughter, Julia, saw Caesar as his necessary instrument. Caesar, once consul, immediately forced through a land bill and, shortly after, another appropriating public lands in Campania. Once he had secured a five-year command in Illyria and Gaul he could be relied on to take off a large proportion of Pompey’s discharged troops and give them further opportunities for profitable employment.

Pompey solved the problem of Rome’s grain supply with his usual efficiency, but the nobles kept up their opposition. The year 56 was a critical one for the triumvirs. The nobles concocted religious impediments to prevent the dispatch of Pompey on a military mission to Egypt, while Publius Clodius contrived to persuade Pompey that Crassus had designs on his life. An attempt was made to suspend Caesar’s law for the distribution of Campanian land.

Alarmed at Pompey’s suspicions and truculence, Crassus set off to meet Caesar at Ravenna, and Caesar in turn came to the limit of his province at Luca to meet Pompey. The Luca conference (56) prepared the ground for the next phase of cooperation: Pompey and Crassus were to secure election to the consulship for 55, for they too wanted five-year commands in the provinces, while Caesar’s command was to be renewed for another five years. The three secured their ends by violence and corruption after a prolonged struggle. Early in 55 Pompey and Crassus were at last elected consuls, with most of the lesser magistracies going to their supporters. Caesar obtained the extension of his command, while Pompey and Crassus received commands in Spain and Syria, respectively. Pompey could stay on in Italy and govern his provinces by deputies. But their cooperation was coming to an end. The death of Julia (54) destroyed the strongest bond between Pompey and Caesar, and Crassus suffered disastrous defeat and death in Mesopotamia. The compact existed no longer, but Pompey as yet showed no inclination to break with Caesar.

Civil war

Meanwhile, from outside the walls of Rome, Pompey watched the anarchy in the city becoming daily more intolerable. He was prepared to wait without committing himself until the Optimates found an alliance with him unavoidable. He refused further offers from Caesar of a marriage alliance. There was talk in Rome as early as 54 of a dictatorship for Pompey. Street violence made it impossible to hold the elections. In January 52 Clodius was killed by armed followers of Titus Annius Milo, whose candidacy for the consulship was being bitterly opposed by both Pompey and Clodius. Now both factions exploded into even greater violence. The senate house was burned down by the mob. With no senior magistrates in office, the Senate had to call on Pompey to restore order. It was the hour he had waited for. He speedily summoned troops from Italy. The nobles would not have him as dictator; they thought it safer to appoint him sole consul.

Pompey’s legislation of 52 reveals his genuine interest in reform and the duplicity of his conduct toward Caesar. He reformed procedure in the courts and produced a panel of respectable jurors. A severe law against bribery at elections was made retrospective to 70 and, for all Pompey’s protests, was rightly taken by Caesar’s friends as aimed at him. Another useful law enforced a five-year interval between tenure of magistracies in Rome and assumption of provincial commands. But this law and another, which prohibited candidature in absence, effectively destroyed the ground of Caesar’s expectation that he should become designated consul, and so safe from prosecution, before he had to disband his army in Gaul. Several attempts were made in the years 51–50 to recall Caesar before the expiration of his second term in Gaul. They were frustrated by the assertiveness of Caesar’s faction and agents in Rome. Pompey, for all his growing fear and suspicion of Caesar’s ambitions, did not come out openly against Caesar until late in 51, when he suddenly made clear his intentions. He declared that he would not consider the suggestion that Caesar should become designated consul while still in command of his army. His proposals for a compromise date for Caesar’s recall were unacceptable to Caesar, whose sole resource now was to use the wealth he had accumulated in Gaul to buy men who could obstruct his enemies in the Senate. When war came, the Senate was evenly divided between Caesar and Pompey. The consulars were solidly for Pompey, although they saw him simply as the lesser evil. Late in 50 the consul Gaius Marcellus, failing to induce the Senate to declare Caesar a public enemy, visited Pompey with the consuls designate and placed a sword in his hands. Pompey accepted their invitation to raise an army and defend the state. Caesar continued to offer compromise solutions while preparing to strike. On January 7, 49, the Senate finally decreed a state of war. Four days later Caesar crossed the Rubicon.

Pompey’s strategic plan was to abandon Rome and Italy to Caesar and rely on his command of the sea and the resources of the East to starve out the Caesarians in Italy, but he did not have the disciplined loyalty and full cooperation of his Optimate allies, and Caesar’s swift advance southward only just failed to prevent his withdrawal from Italy. Across the Adriatic at Dyrrhachium (now Durrës, Albania) the wisdom of Pompey’s strategy became clear. Caesar, after a hazardous crossing in pursuit, found himself cut off from his base in Italy by sea and facing superior land forces. Pompey, however, eventually had to abandon his naval blockade of the rest of Caesar’s forces in Brundisium and failed to prevent their crossing to join Caesar. Caesar’s army was repulsed in an assault on Pompey’s camp at Dyrrhachium and, failing a quick decision in the West, Caesar was obliged to move eastward into Thessaly. Pompey followed and joined forces with the Senate’s army there under Scipio, rendering Caesar’s position untenable. At this juncture, Pompey, under pressure from his Optimate allies, decided for battle, a sensible enough decision if his opponent had not been a commander of genius. Pompey suffered a disastrous defeat on the plain of Pharsalus (48). He fled from his camp as the enemy stormed it and made his way to the coast. His supporters were to rally and involve Caesar in strenuous fighting in Africa, Spain, and the East for three more years, but Pompey did not live to play a part in this struggle. Hurried on by Caesar’s rapid pursuit, he lost contact with his own fleet. He moved on southward to Cilicia, Cyprus, and Egypt. He decided to land at Pelusium and seek the assistance of Ptolemy, his former client. The king marched down to the coast, ostensibly to welcome him, but he and his counsellors had chosen not to risk offending the victorious Caesar. Pompey’s small squadron lay offshore while Pompey, bidding farewell to his wife, Cornelia, complied with an insidious invitation to enter, with several companions, a small boat sent to bring him to land. As he prepared to step ashore, he was treacherously struck down and killed (September 28, 48 bce).