The Bellum Octavianum, or “War of Octavius,” was a significant Roman republican civil war fought in 87 BC. It was primarily a conflict between the year’s two consuls, Gnaeus Octavius and Lucius Cornelius Cinna. This war was sparked by deep political tensions concerning the enfranchisement of Italian citizens and culminated in the victory of Cinna, who, alongside Gaius Marius, seized control of Rome by late 87 BC.

Political Tensions and the Aftermath of the Social War

The Social War (91–88 BC) had significantly altered the Roman political landscape. Following the war, the lex Julia of 90 BC granted Roman citizenship to many Italian allies. However, their enfranchisement came with restrictions: these new citizens were assigned to only a few tribes, diluting their political influence compared to the existing Roman citizenry.

Publius Sulpicius Rufus, a plebeian tribune, sought to distribute these new citizens among all 35 voting tribes, thus amplifying their political voice. This proposal faced fierce opposition, notably from Sulla and the Senate. Sulpicius’ radical reforms, combined with the political ambitions of Gaius Marius, led to Sulla’s first march on Rome in 88 BC. This unprecedented act by Sulla temporarily restored order but left deep divisions within the Roman state.

The Consuls of 87 BC: Gnaeus Octavius and Lucius Cornelius Cinna

In 87 BC, Gnaeus Octavius and Lucius Cornelius Cinna were elected consuls. Sulla, departing for his campaign against Mithridates VI of Pontus, compelled both consuls to swear an oath to uphold his laws. Despite this, Cinna renewed efforts to enfranchise the new Italian citizens and to recall the exiled Marius. Octavius opposed these measures, setting the stage for open conflict.

The Outbreak of War

Cinna’s proposal to integrate the new citizens into all tribes reignited political tensions. Octavius, with the support of a majority of the tribunes, blocked Cinna’s measures, leading to riots in the Forum. Violence erupted between the factions, with Octavius’ supporters allegedly massacring Italians allied with Cinna. Forced out of Rome, Cinna declared himself the legitimate consul and began raising an army. The Senate, siding with Octavius, declared Cinna a hostis (enemy of the state) and replaced him with Lucius Cornelius Merula, the flamen Dialis (priest of Jupiter).

Cinna’s Military Campaign

Cinna traveled to Nola, where he took control of the Roman army stationed there. He gained the allegiance of these troops by appealing to their grievances, presenting himself as a champion of their rights and Roman tradition. Marius, meanwhile, returned from exile and joined forces with Cinna in Etruria. Together, they raised a substantial force, with Cinna’s army eventually outnumbering Octavius’ troops.

The Siege of Rome

Cinna and Marius adopted a strategy to starve Rome into submission. They divided their forces into three groups: Marius controlled the access to Ostia, cutting off Rome’s supplies, while Cinna and Sertorius besieged the city’s gates. Octavius’ forces, supported by Pompeius Strabo and Quintus Caecilius Metellus Pius, initially resisted but were weakened by disease and defections.

The Samnites, a former enemy of Rome, joined Cinna after securing favorable terms, further bolstering his forces. Despite Octavius achieving a temporary victory near the Janiculum, his position became untenable as plague decimated his ranks, and Strabo’s death led to a mass defection of his troops.

The Fall of Rome

With famine and internal strife crippling the city, the Senate was forced to negotiate with Cinna. Lucius Cornelius Merula abdicated the consulship, and the Senate recognized Cinna’s authority. Upon entering Rome, Cinna and Marius initiated a brutal purge of their political opponents. Gnaeus Octavius was killed, and his head was displayed in the Forum. Prominent figures such as Quintus Lutatius Catulus and Merula committed suicide, while others faced execution or manipulated trials.

The Aftermath and Cinna’s Rule

After their victory, Cinna and Marius declared themselves consuls. Marius, in his seventh and final consulship, died shortly after taking office in 86 BC. Cinna continued to dominate Roman politics, maintaining control until his death in 84 BC. During his tenure, Cinna annulled Sulla’s reforms, recalled exiles, and secured loyalty from key factions, but he failed to address the deeper systemic issues plaguing Rome.

Key Players and Their Roles

Lucius Cornelius Cinna

Cinna emerged as a leader of the populares faction, advocating for the rights of the new Italian citizens. His ability to rally troops and secure alliances, particularly with Marius and the Samnites, was pivotal to his success.

Gnaeus Octavius

Octavius, representing the optimates faction, sought to preserve the traditional privileges of Rome’s old citizenry. His failure to maintain unity among his allies and to counteract disease and desertions ultimately led to his downfall.

Gaius Marius

Marius, a legendary general and six-time consul, returned from exile to play a central role in the conflict. His military expertise and personal vendettas shaped the course of the war and its aftermath.

Quintus Sertorius

Sertorius, a skilled lieutenant under Cinna, contributed to the strategic success of the siege, demonstrating tactical acumen that foreshadowed his later campaigns in Spain.

Impact on Rome

The Bellum Octavianum highlighted the fragility of the Roman Republic. The war exacerbated existing divisions between the populares and optimates, setting a precedent for future conflicts. It also underscored the dangers of personal ambition and the militarization of politics, trends that would culminate in the fall of the Republic.

Short-Term Consequences

• Political Purges: The deaths of Octavius, Merula, and other prominent figures marked a turning point in the use of violence as a political tool.
• Cinnan Regime: Cinna’s dominance over Rome created a temporary stabilization but failed to resolve underlying tensions.

Long-Term Effects

• Sulla’s Return: The defeat of Cinna’s faction in 83 BC during Sulla’s second march on Rome led to the dictator’s rise to power.
• Institutional Weakening: The repeated use of armies to settle political disputes eroded the Republic’s foundations, paving the way for the eventual emergence of the Roman Empire.

The True Extent of the Roman Empire

Frequently Asked Questions

What caused the Bellum Octavianum?

The war was triggered by disputes over enfranchising Italian citizens into voting tribes and recalling Gaius Marius from exile. Tensions escalated when Octavius opposed these measures, leading to Cinna’s expulsion and subsequent military mobilization.

What role did Marius play in the conflict?

Marius joined Cinna’s side after raising an army in Africa. He captured and sacked Ostia, cutting off Rome’s supplies, and contributed significantly to the siege of Rome.

What was the significance of the siege of Rome?

Cinna and Marius besieged Rome, starving the city into submission. They divided their forces strategically, capturing key locations like Ostia and Lanuvium, which forced the Senate to negotiate.

How did Octavius and his allies respond?

Octavius and Merula fortified Rome and raised troops, but internal disagreements and a plague weakened their efforts. Pompeius Strabo played both sides, further complicating Octavius’ position.

What happened after Cinna and Marius entered Rome?

They executed political opponents through trials and killings, including Octavius, while overturning Sulla’s laws. Marius and Cinna declared themselves consuls, establishing dominance until Sulla’s return.

What was the impact on Roman politics?

The conflict marked a shift toward violent factionalism in Roman politics, with Marius’ death in 86 BC and Cinna’s eventual assassination in 84 BC setting the stage for Sulla’s civil war.

Top 10 Ancient Roman Generals and their Notable Accomplishments