Ancient Rome · 107–78 BCE

Marius and Sulla: How Rome's Army Turned on the Republic

By the Aurelius editorial team · 3 min read · Updated 15 October 2026

Last time: the Gracchi tried to give land to poor citizens and were killed. The problem they raised, who provides for Rome's soldiers, was still open.

In 88 BCE, the consul Lucius Cornelius Sulla told his legions at Nola that politicians in Rome had taken their eastern command away. The soldiers urged him to march on the city, and when all but one of his officers walked out, the soldiers followed him anyway.

The new man from Arpinum

Gaius Marius came from Arpinum, a country town, and no one in his family had held high office in Rome: he was a novus homo, a “new man”. A soldier first, blunt and proud of his lack of Greek polish, he won the consulship for 107 BCE by promising to finish a stalled war against Jugurtha, king of Numidia.

To fill his ranks, Marius enrolled volunteers from the capite censi, citizens too poor to be registered by property at all. Historians now doubt this was a single “Marian reform”, since property requirements had been falling for decades. But the change mattered. Poor recruits looked to their general, not the state, for pay, plunder and land when they retired.

Seven consulships

In 105 BCE migrating Germanic peoples, the Cimbri and Teutones, destroyed a Roman army at Arausio in southern Gaul, one of Rome's worst defeats since Cannae. Rome turned to Marius and elected him consul five years running, from 104 to 100 BCE, in defiance of custom.

Marius drilled his men hard, made them carry their own kit (they were nicknamed “Marius's mules”) and made the eagle the standard of every legion. He crushed the Teutones in 102 BCE and the Cimbri in 101. Rome had found a saviour, and had learned to bend its rules for one.

The patrician with the signet ring

Sulla was everything Marius was not: heir to an ancient patrician name but no money, cultured and charming, fond of actors and late nights, and ruthless. Serving under Marius in Africa in 105 BCE, he persuaded King Bocchus of Mauretania to betray Jugurtha, and received the captive king himself.

Marius celebrated the triumph, but Sulla wore a signet ring showing the surrender, and Marius never forgave him. When Rome's Italian allies rebelled to win citizenship in the Social War of 91–88 BCE, it was Sulla, not the ageing Marius, whose reputation grew.

The march on Rome

In 88 BCE Sulla, now consul, was given command against Mithridates VI of Pontus, who had overrun Rome's province of Asia. The command promised glory and plunder. A tribune, Sulpicius, then passed a law transferring it to Marius. Sulla went to his army, and his army went with him to Rome.

No Roman general had ever led his troops into the city. Sulla seized it, outlawed Marius, who fled to Africa, and left for the East. Once he was gone, Marius returned alongside the consul Cinna and massacred their enemies. Elected consul for a seventh time in 86 BCE, Marius died within weeks.

Dictator with a list

Sulla came back in 83 BCE, won a civil war at Rome's Colline Gate in 82 and had himself appointed dictator, the first in 120 years, with no time limit. Then he posted lists of names in the Forum. Anyone “proscribed” could be killed for a reward; their property was sold and their sons were barred from office. Thousands died, though ancient totals vary.

Sulla used his power to strengthen the Senate and cripple the tribunes. Then, astonishingly, he gave it up, served a last term as consul in 80 BCE, retired and died in 78. But he had shown that an army loyal to its general could take Rome. Among those he spared was a defiant young man married to Cinna's daughter: Gaius Julius Caesar.

In their own words

“He himself in the meantime enrolled soldiers, not according to the classes in the manner of our forefathers, but allowing anyone to volunteer, for the most part the proletariat.”

Sallust, The War with Jugurtha 86.2, c. 41–40 BCE

Translation after J. C. Rolfe (Loeb Classical Library). Sallust, a partisan of Caesar, wrote some 65 years later, and adds that some thought Marius did it for lack of better men, others to court the poor who had elected him.

Why it happened

• The land problem the Gracchi raised was left unsolved, and the legions needed recruits.
• Emergencies against Jugurtha and the Cimbri led Rome to bend its rules for Marius.
• Soldiers came to depend on their generals for rewards, and so to follow them.
• Personal rivalry between Marius and Sulla turned a dispute over a command into civil war.

What happened next

• Sulla's march on Rome made it thinkable for a general to use his army in politics. Read the story →
• Proscription became a model: in 43 BCE Octavian, Antony and Lepidus revived it. Read the story →
• Rome's Italian allies won citizenship after the Social War, turning Rome into a citizen body the size of Italy.

Why it still matters

Roman soldiers swore their military oath, the sacramentum, to their commanding general. Modern democracies take care to do the opposite: a US military officer swears to “support and defend the Constitution of the United States”, an oath to a document rather than a person. It is the lesson Rome learned too late: an army's loyalty must belong to the state, not to the general who pays it.

Connected stories

• The Gracchi and the Crisis of the Republic: The Gracchi's failure to solve the land problem left soldiers' rewards in the hands of generals.
• Caesar Crosses the Rubicon: Caesar, Marius's nephew by marriage, would follow Sulla's example and march on Rome.
• The Punic Wars: Rome Against Carthage: Driven from Italy in 88 BCE, Marius is said to have sat among the ruins of Carthage, the city Rome destroyed in 146 BCE.

Sources

• Plutarch, Lives of Marius and Sulla
• Sallust, The War with Jugurtha 84–86
• Appian, Civil Wars 1.55–1.106
• Mike Duncan, The Storm Before the Storm: The Beginning of the End of the Roman Republic (2017)

Images are credited under each picture. Paintings and photographs come from public collections via Wikimedia Commons; scenes with no surviving image are marked as illustrations.