The two armies met here in a life and death struggle, Cnæus Pompeius appealing to his men to avenge his father, while Cæsar’s veterans, responding to the battle cry of Venus the Victorious, the patron goddess of the Cæsarian house and its mythical foundress, made it plain that the cause for which they fought was also a personal one. Neither side could look for quarter; Pompeius had already shown his temper by cruel dealings with the provincials who had opposed him, and Cæsar’s men were not likely to deal mercifully with those who had rekindled the flame of civil war and so deprived them of a well-earned peace. Both in attack and defense each side showed equal bravery and obstinacy. For some time the issue seemed dubious; Cæsar to rally his own men had to take sword in hand and engage in the thick of the struggle. Finally, when the Pompeians made a change of their order to help the wing of their army which was being hard pressed by the tenth legion, the movement gave the Cæsarians a chance to put their opponents in confusion and finally to flight. On the Pompeian side 30,000 are reported to have been slain; among the dead were Labienus, Cæsar’s right-hand man in the Gallic campaign, and Cnæus Pompeius himself, who escaped from the field but was taken and put to death afterward.

Before the return to Italy the affairs of the Spanish provinces had to be set in order; special favors were distributed to the loyal communities in the way of franchise or immunities, and this reconstructive work seems to have been accompanied by financial exactions. The return to Italy was not made until September, and for a whole month Cæsar remained outside the walls of Rome. To mark the victory at Munda there was nothing tangible to do in the way of increasing the autocratic power of the supreme and all-embracing magistrate and executive; there were, however, no visible limitations to the servility of the Senate and Assembly. Fifty days’ thanksgiving, yearly games commemorative of the victory, special distinctions of dress, extraordinary honorific titles, a state residence on the Palatine, built after the model of a temple of the gods; special statues in holy places connected with communal worship, all these were voted, and most of them accepted by the conqueror.

After the Spanish war, gold and silver coins were minted, having on one side the laurel-crowned head of Cæsar, with the inscription Cæsar Imperator, and on the reverse the figure of conquering Venus, lance in one hand and on the other a Victory. The conqueror was now treated as being beyond the ordinary human standard. This recognition of superhuman qualities is made plainer in an inscription, placed under a relief of Cæsar (introduced on a metallic map of the world), which reads, “he is a demigod.” The Oriental idea of deification, opposed as it was to the whole genius of government in Rome, was now adopted there. With Julius Cæsar began the custom of deifying the supreme ruler of Rome, and it is significant that, although he refused a ten-year consulship, he did not protest against this use of religion for the purpose of adulation.

Now that the supreme authority was unassailably placed in the hands of a single individual, who was protected in its exercise from any legal opposition in Rome, Cæsar showed no hesitation in taking the full responsibility of his position. The Western provinces had for some time been practically under his personal control. He was virtually the founder and the creator of the Roman Empire in the West. The foundation laid by him lasted for hundreds of years. But as military lord of the Roman world he had also to deal with the situation of the East. There especially the extension of the Parthian rule was dreaded, and also anticipated, for the moral effect of the defeat of Crassus a few years before had been immense. Cæsar saw that a war in the East could alone restore the prestige of Rome, and also that it was not safe to leave the conduct of such a war in other hands. His plan was first to conquer the Parthians, and through their territory to reach the Caspian Sea. Afterwards by the way of the Black Sea he meant to march along the Danube, where there were wild tribes which had to be taught to respect the power of Rome, and finally to return to Italy by the way of Germany. Such was the mighty program now developed in the vision of the conqueror. In its details it bore the marks of the bold imagination and the political sagacity which characterized his genius, but the immediate necessity was to bring the Parthian war to an end, and so restore confidence on the Eastern frontier. After the return from Spain the transfer of the bulk of the Roman army to the East was being prepared for.

It was in connection with this purpose that there first arose, apparently, the idea of conferring on Cæsar the title of king. It was said that an oracle of the Sibylline Books had declared that only a king could get the better of the Parthians in war. Such a designation was especially antagonistic to Roman political principles; personal rule was tolerated, but not divine right by family descent. Some preparations had been made for the introduction of this alien conception by the act of the Senate, according to which the title “Imperator,” associated directly with the name of Cæsar, should pass to his legal heir. The road to a succession being now marked out, the whole question of the title could not long be left undecided. Imperator was locally understood, but made no claim on subject races. To test popular feeling, Marcus Antonius offered the Imperator a diadem, the insignia of royalty. This was refused, but it was noted that the offer did not call forth the enthusiastic response that was anticipated, nor was Cæsar’s rejection of the symbol openly deplored. Still, the desire for some accommodation with the terms of the oracle was not abandoned. It seemed possible that in Rome Cæsar might bow to public opinion by employing only the title of Imperator, while in the provinces he could exercise royal powers and use the royal title. It was supposed that some arrangement of this sort would be made by a regular decree before he set out for the Parthian campaign.

Opposition was bound to develop at this point from the convinced republicans in the Senate; they were strongly represented there, and Cæsar was responsible for their presence. He had gathered about him men of both parties, making a special effort by his generosity to win over some of the most convinced of the senatorial partisans who had followed Pompeius and had fought the victor to the end of the African campaign. But even Cæsar’s own appointees and adherents were by no means reconciled to the program which would openly do away with the republic; they wished it still to exist as an institution, and they had no wish to provide for the continuance of personal rule beyond the terms of Cæsar’s own life.

The party of Pompeius was by no means inactive; they wrote freely as apologists for their own side, and they did not hesitate in their intrigues to hold up Cæsar as an ambitious autocrat guilty of cruelty on the battlefield, and now that peace was restored, using his claims to mask his aim to establish a tyranny. These views were found among the Senators. Cæsar either thought he was unassailable or reckoned on their gratitude as an obstacle which would separate their theory and their practice. This attitude was only one example of a general want of alertness that seemed to characterize the conqueror after the close of the Spanish campaign.

All the old republican antipathies against royalty were called into life. Cæsar’s statue was now seen on the capitol between the figures of Rome’s ancient kings. Another statue, that of Lucius Junius Brutus, the founder of the republic, recalled to men’s minds the quick and ready method of dealing with kings and tyrants. This old-fashioned republican doctrine was not lost on a disciple and nephew of Cato, Marcus Brutus, who had made peace with Cæsar after the battle of Pharsalus. He claimed to be a descendant of the famous liberator, and by this very fact had influence in heading any movement against the new autocratic system. His personal abilities were of a mediocre order; but he was obstinate and self-consciously vain of his integrity, and could be paraded as a concrete argument to strengthen the republican cause, when others might hesitate to take extreme steps.

But the real motive power in the organization of the conspiracy against Cæsar was found in Caius Cassius, also holding prætorian office like Brutus. The two had not before been friendly, although both were partisans of Pompeius. Cassius, with his dark and gloomy temperament and sarcastic tongue, was not likely to accept the sententious pomposity of his brother Prætor at that high standard of value exacted by Brutus from his friends. What drew them together was their common republican sympathies. Brutus was asked by Cassius what would be his attitude at the next meeting of the Senate when the question of the royal title would be discussed. Brutus replied that he would not be present. Cassius said that Brutus’s position as Prætor imposed upon him the obligation of attending the meeting. At this Brutus answered that if he went he would defend the cause of liberty.

Such was the basis of the understanding between the two, and the agreement for common action was accepted, not only by the remnant of the old Pompeian party, but by those as well who called themselves the partisans of Cæsar. Even Caius Trebonius, who had served the cause of Cæsar in the city and on the battlefield for many years, agreed that the freedom of the Roman people was to be preferred to the friendship of an individual. He had once before spoken plainly to Marcus Antonius of Cæsar’s ingratitude and of the misfortunes of the republic, but had found no sympathy. Another of Cæsar’s companions in arms, Tullius Cimber, felt personally injured because the commander had exiled his brother.