Perusine War (41 BC to 40 BC) and Fulvia's death
In 42 BC, Antony and Octavian left Rome to pursue Julius Caesar's assassins, Marcus Junius Brutus and Gaius Cassius Longinus. Fulvia was left behind as the most powerful woman in Rome, seeing as though she had already manifested her political aptitudes throughout the decades. According to Cassius Dio, Fulvia controlled the politics of Rome. Dio wrote that "the following year Publius Servilius and Lucius Antonius nominally became consuls, but in reality it was Antonius and Fulvia. She, the mother-in‑law of Octavian and wife of Antony, had no respect for Lepidus because of his slothfulness, and managed affairs herself, so that neither the senate nor the people transacted any business contrary to her pleasure."
Shortly afterwards, the triumvirs distributed the provinces among themselves. Lepidus took the west and Antony went to Egypt, where he met Cleopatra VII. Octavian returned to Rome in 41 BC to dispense land to Caesar's veterans, divorced Fulvia's daughter and accused Fulvia of aiming at supreme power. Fearing that Octavian was gaining the veterans' loyalty at Antony's expense, Fulvia traveled constantly with her children to the new settlements in order to remind the veterans of their debt to Antony. Fulvia also tried to delay the land settlements until Antony returned to Rome, so that the two triumvirs could share the credit. With Octavian in Italy and Antony abroad, Fulvia allied with her brother-in-law Lucius Antonius and publicly endorsed Mark Antony in opposition to Octavian.
These actions caused political and social unrest. In 41 BC, tensions between Octavian and Fulvia escalated to war in Italy: the Perusine War of 41-40 BC. According to Appian, Fulvia was a central cause of the war, due to her jealousy of Antony and Cleopatra's affair in Egypt; she may have escalated the tensions between Octavian and Lucius in order to draw back Antony's attention to Italy. However, Appian also wrote that the other main causes were the selfish ambitions of the commanders and their inability to control their own soldiers.
Together with Lucius Antonius, Fulvia raised eight legions in Italy to fight for Antony's rights against Octavian, an event known as the Perusine War. The army occupied Rome for a short time, and Lucius organized his troops at Praeneste, but eventually retreated to Perusia (modern Perugia), where Octavian besieged him. Lucius waited for Antony's legions in Gaul to come to his aid. However, unaware of the war, Antony was still in the eastern provinces, and his legions were unsure of his commands and did not assist Lucius. Although during this conflict, Fulvia was at Praeneste, there is evidence she helped Lucius. According to Appian, she "urged Ventidius, Asinius, and Calenus from Gaul to help Lucius, and having gathered another army, she sent it to Lucius under the command of Plancus."
During the war, Octavian's soldiers at Perusia used sling bullets inscribed with insults directed at Fulvia personally and Octavian wrote a vulgar epigram directed at her in 40 BC, referring to Antony's affair with the ex-courtesan queen of Cappadocia Glaphyra. It is recorded by Martial within one of his own poems:
The sling bullets are very significant because they demonstrate the gender dynamics of Rome at that time. The sling- bullets are a playful metaphor, aimed at degrading and mocking Fulvia for her masculine tendencies. The bullets were shaped like a penis tips, and they share the same Latin technical term "glans.". The fact that her name is written on bullets shaped like a penis tip points to the idea that she embodies masculine characteristics and is being thus ridiculed. Her assertiveness and boldness is being vilified and intended to undermine her legitimacy.
The siege at Perusia lasted two months before Octavian starved Lucius into surrender in February 40 BC. After Lucius' surrender, Fulvia fled to Greece with her children. Appian writes that she met Antony in Athens, and he was upset with her involvement in the war. Antony then sailed back to Rome to deal with Octavian, and Fulvia died of an unknown illness in exile in Sicyon, near Corinth, Achaea. After her death, Antony and Octavian used it as an opportunity to blame their quarrelling on her. According to Plutarch, "there was even more opportunity for a reconciliation with Caesar [i.e., Octavian]. For when Antony reached Italy, and Caesar manifestly intended to make no charges against him, and Antony himself was ready to put upon Fulvia the blame for whatever was charged against himself."
After Fulvia's death, Antony married Octavian's sister, Octavia Minor, to publicly demonstrate his reconciliation with Octavian, but Antony never regained his position and influence in Italy.
Once Antony and Octavia were married, she took in and reared all of Fulvia's children. The fate of Fulvia's daughter, Clodia Pulchra, after her divorce from Octavian is unknown. Her son Marcus Antonius Antyllus was executed by Octavian in Alexandria, Egypt in 30 BC. Her youngest child, Iullus Antonius, was spared by Octavian and raised from 40 BC by Octavia Minor. Iullus married Octavia's daughter and Octavian's niece Claudia Marcella Major and they had a son Lucius Antonius and possibly a daughter Iulla Antonia.