Octavius and the consuls assembled their forces at Alba. On the first day of the new year (43) Hirtius marched for Mutina, with Octavius under his command. The other consul, Pansa, remained at Rome to raise new levies; but by the end of March he also marched to form a junction with Hirtius. Both parties pretended to be acting in Cæsar's name.
Antony left his brother Lucius in the trenches before Mutina, and took the field against Hirtius and Octavius. For three months the opponents lay watching each other. But when Antony learned that Pansa was coming up, he made a rapid movement southward with two of his veteran legions and attacked him. A sharp conflict followed, in which Pansa's troops were defeated, and the consul himself was carried, mortally wounded, off the field. But Hirtius was on the alert, and assaulted Antony's wearied troops on their way back to their camp, with some advantage. This was on the 15th of April, and on the 27th Hirtius drew Antony from his intrenchments before Mutina. A fierce battle followed, which ended in the troops of Antony being driven back into their lines. Hirtius followed close upon the flying enemy; the camp was carried by storm, and a complete victory would have been won had not Hirtius himself fallen. Upon this disaster Octavius drew off the troops. The news of the first battle had been reported at Rome as a victory, and gave rise to extravagant rejoicings. The second battle was really a victory, but all rejoicing was damped by the news that one consul was dead and the other dying. No such fatal mischance had happened since the Second Punic War, when Marcellus and Crispinus fell in one day.
After his defeat Antony felt it impossible to maintain the siege of Mutina. With Dec. Brutus in the town behind him, and the victorious legions of Octavius before him, his position was critical. He therefore prepared to retreat, and effected this purpose like a good soldier. His destination was the province of Narbonnese Gaul, where Lepidus had assumed the government and had promised him support. But the senate also had hopes in the same quarter. L. Munatius Plancus commanded in Northern Gaul, and C. Asinius Pollio in Southern Spain. Sext. Pompeius had made good his ground in the latter country, and had almost expelled Pollio from Bætica. Plancus and Pollio, both friends and favorites of Cæsar, had as yet declared neither for Antony nor Octavius. If they would declare for the senate, Lepidus, a feeble and fickle man, might desert Antony; or if Octavius would join with Dec. Brutus, and pursue him, Antony might not be able to escape from Italy at all. But these political combinations failed. Plancus and Pollio stood aloof, waiting for the course of events. Dec. Brutus was not strong enough to pursue Antony by himself, and Octavius was unwilling, perhaps unable, to unite the veterans of Cæsar with troops commanded by one of Cæsar's murderers. And so it happened that Antony effected his retreat across the Alps, but not without extreme hardships, which he bore in common with the meanest soldier. It was at such times that his good qualities always showed themselves, and his gallant endurance of misery endeared him to every man under his command. On his arrival in Narbonnese Gaul he met Lepidus at Forum Julii (Frejus), and here the two commanders agreed on a plan of operations.
The conduct of Octavius gave rise to grave suspicions. It was even said that the consuls had been killed by his agents. Cicero, who had hitherto maintained his cause, was silent. He had delivered his Fourteenth and last Philippic on the news of the first victory gained by Hirtius. But now he talked in private of "removing" the boy of whom he had hoped to make a tool. Octavius, however, had taken his part, and was not to be removed. Secretly he entered into negotiations with Antony. After some vain efforts on the part of the senate to thwart him, he appeared in the Campus Martius with his legions. Cicero and most of the senators disappeared, and the fickle populace greeted the young heir of Cæsar with applause. Though he was not yet twenty he demanded the consulship, having been previously relieved from the provisions of the Lex Annalis by a decree of the senate, and he was elected to the first office in the State, with his cousin, Q. Pedius.[[80]]
[!-- Note Anchor 80 --][Footnote 80: Pedius was son of Cæsar's second sister, Julia minor, and therefore first cousin (once removed) to Octavius.]
A curiate law passed, by which Octavius was adopted into the patrician gens of the Julii, and was put into legal possession of the name which he had already assumed—C. Julius Cæsar Octavianus. We shall henceforth call him Octavian.
The change in his policy was soon indicated by a law in which he formally separated himself from the senate. Pedius brought it forward. By its provisions all Cæsar's murderers were summoned to take their trial. Of course none of them appeared and they were condemned by default. By the end of September Octavian was again in Cisalpine Gaul and in close negotiation with Antony and Lepidus. The fruits of his conduct soon appeared. Plancus and Pollio declared against Cæsar's murderers. Dec. Brutus, deserted by his soldiery, attempted to escape into Macedonia through Illyricum; but he was overtaken near Aquileia and slain by order of Antony.
Italy and Gaul being now clear of the senatorial party, Lepidus, as mediator, arranged a meeting between Octavian and Antony, upon an island in a small river near Bononia (Bologna). Here the three potentates agreed that they should assume a joint and coordinate authority, under the name of "Triumvirs for settling the affairs of the Commonwealth." Antony was to have the two Gauls, except the Narbonnese district, which, with Spain, was assigned to Lepidus; Octavian received Sicily, Sardinia, and Africa. Italy was for the present to be left to the consuls of the year, and for the ensuing year Lepidus, with Plancus, received promise of this high office. In return, Lepidus gave up his military force, while Octavian and Antony, each at the head of ten legions, prepared to conquer the Eastern part of the empire, which could not yet be divided like the Western provinces, because it was in possession of Brutus and Cassius.
But before they began war, the triumvirs agreed to follow the example set by Sylla—to extirpate their opponents by a proscription, and to raise money by confiscation. They framed a list of all men's names whose death could be regarded as advantageous to any of the three, and on this list each in turn pricked a name. Antony had made many personal enemies by his proceedings at Rome, and was at no loss for victims. Octavian had few direct enemies; but the boy-despot discerned with precocious sagacity those who were likely to impede his ambitious projects, and chose his victims with little hesitation. Lepidus would not be left behind in the bloody work. The author of the Philippics was one of Antony's first victims; Octavian gave him up, and took as an equivalent for his late friend the life of L. Cæsar, uncle of Antony. Lepidus surrendered his brother Paullus for some similar favor. So the work went on. Not fewer than three hundred senators and two thousand knights were on the list. Q. Pedius, an honest and upright man, died in his consulship, overcome by vexation and shame at being implicated in these transactions.
As soon as their secret business was ended, the triumvirs determined to enter Rome publicly. Hitherto they had not published more than seventeen names of the proscribed. They made their entrance severally on three successive days, each attended by a legion. A law was immediately brought in to invest them formally with the supreme authority, which they had assumed. This was followed by the promulgation of successive lists, each larger than its predecessor.