On March 15, 44 BC, the Roman world was shaken to it's foundation with the assassination of Julius Caesar. Though the effect would prove to be staggering, (ie the plunge into yet another devastating civil war), no Roman was as profoundly affected as Gaius Octavius. Nearly 19 years old, Octavian was studying in Apollonia and awaiting the start of Caesar's next campaign against Parthia. Octavian's plan to join this campaign came to a crashing halt with the murder of his great uncle, and two equally possible roads soon opened to the young man.
When word reached Octavian of Caesar's murder, the naming of Octavian as his uncle's heir and posthumous adoption, reaction was mixed among his family and friends. His friends, likely Agrippa included, urged him to go to Macedonia and take refuge with Caesar's former legions there. His mother and step-father, L. Marcius Philippus on the other hand, pressed him to return to Rome as a private citizen and refuse Caesar's inheritance out of fear for his personal safety. Octavian sided in part with his family and decided to return to Rome, but readily accepted the adoption and the portion of Caesar's estate that was willed to him. He took the name Gaius Julius Caesar Octavianus, as was his right by virtue of adoption, but Octavianus was dropped from conscious thought. It's been used throughout the study of history to define him from his adoptive father, but he identified himself simply as Caesar. In so doing, he immediately entrenched himself as a favorite both with the masses and the all important veteran legionaries.
After making the decision to return to Rome to claim his inheritance, Octavian first crossed the Adriatic and landed in Brundisium, where he decided the safest course of action was an appeal to Caesar's troops. A bold and daring move, and seemingly necessary to ensure his safety, it turned out to be the only way to ensure his legitimacy. As Octavian marched to Rome, and gathered support among Caesar's Italian veterans, the de facto leader in Rome, Marcus Antonius, essentially ignored the youth. Not only did he blatantly disregard Caesar's will, but made no effort to discuss the situation with Octavian or learn of his intentions. When Octavian finally arrived in Rome in late April, 44 BC, Antony still ignored him, and still attempted to block passing on Caesar's inheritance. Octavian, however, garnered support from the masses and conflict seemed inevitable.
Antony was occupied with his own intentions of taking Cisalpine Gaul from then governor Decimus Brutus. Though the use of the Tribunes, Antony forced through legislation that altered his appointed governership of 43 BC from Macedonia to Cisalpine Gaul. Decimus Brutus, a former supporter of Caesar, yet a key player in the assassination, had the general support of the Senate, and of course, Caesar's assassins. Antony, however, had no intention of waiting for events to unfold and took matters in his own hands. In November of 44 BC, rather than wait for Decimus Brutus' term to expire, Antony moved on Cisalpine Gaul, where he hoped to gather further strength by pushing his control into all of Gaul. In the meantime Octavian, as he was being set aside by the powers that were as a man with a name but no authority, pushed the envelope of daring. He traveled among the veteran colonies of Campania and, risking the enmity of the state, raised a personal army perhaps as strong as 10,000 men. The weight of the Caesar name, as Octavian was still quite unaccomplished on his own merit, proved to be a powerful factor to reckon with.
Antony returned to Rome to deal with this new threat, but 2 of his 5 legions on the way from Macedonia to Gaul deserted him to Octavian's growing army. Rather than risk a war in Italy, Antony rushed back to Cisalpine Gaul with the forces he could muster, where he hoped to seize control from Brutus. At this point, there were three seemingly opposed factions vying for power, the 'Liberators' or Caesar's assassins, Antony and Octavian. The Senate, and Cicero in particular all viewed Antony as the greatest threat to Republican liberty, and he began a campaign of disgracing Antony through the use of his vaunted rhetoric. Viewing Octavian as a tool to be manipulated, the Senate accepted him as a counterforce to Antony's strength and legitimized his command, despite its illegal beginnings. By the close of 44 BC, the various factions continued to shore up their military positions, and war was once again on the horizon.