The Jugurthine War and the Great Threat from the North: The Year 107 BCE

View of the Forum Romanum.


  • The concilium plebis gives command of the Jugurthine War to the consul Gaius Marius;
  • Marius openly recruits part of his soldiers from the class of the proletarii (the ‘Marian’ reforms);
  • Marius captures Capsa by surprise, burns the city to the ground and massacres the male population;
  • The Tigurini, allies of the Cimbri and Teutones, defeat and kill the consul Lucius Cassius Longinus.

Gaius Marius was almost fifty years old when he started his term of office as consul on 1 January of this year. His main goal was to end the war against Jugurtha, but it was the Senate that selected the provinces (before the consular elections) and granted them to magistrates. According to Sallustius, the Senate had decided grant Numidia and the war against the Numidian king to Quintus Caecilius Metellus, who had been fighting in the region for almost two years and whose legate Marius had been. Our historian claims it was the people’s tribune Titus Manlius Mancinus who asked the concilium plebis to give the command to Marius. The plebs readily adopted his proposal and Marius became commander-in-chief of the war he so desired. He immediately began preparations, and strengthening the army was high on his list.

The ‘Marian’ reforms

Republican legionaries, late 2nd century BCE (photo: Jastrow).

The Roman army had always been an army of conscripts. Soldiers were traditionally recruited from the propertied classes, with middle class farmers forming the backbone of the legions. As the second century progressed, there were ever greater problems with recruiting enough men. Volunteers became increasingly scarce, and conscription became hugely unpopular. Sometimes young Romans feigned illnesses to prevent being drafted into the legions (see 151 BCE). The authorities had tried to solve these problems by lowering the property qualifications for serving in the legions and by issuing state-produced weapons and armour to citizens who could not afford their own equipment. Tiberius Gracchus’ land reforms of 133 BCE need to be seen against this background as well: poor citizens who were granted public land (ager publicus) became part of the propertied classes again and were therefore eligible for military service. Tiberius’ brother Gaius Gracchus had tried to stop the illegal practice of recruiting boys under the age of seventeen for the army.

The aforementioned measures were not sufficient though, and Marius went one step further: he was the first magistrate to openly recruit part of his soldiers from the class of the proletarii, the people without property, literally ‘they who only have their children’ (proles). They were also known as the capite censi, as the censors only counted their heads during the census. These men had no property, and therefore no weapons or body armour. It was up to the commanding general or the state to provide them with whatever equipment they needed and to pay them for their services. Serving in the army now became a career. Unlike the farmers from the Mid-Republic, the proletarii who joined the legions were career soldiers and had no civilian life or profession to return to after completing their military service. The ‘Marian’ reforms marked the first step towards a professional army.

Replica of a Roman gladius (left).

The ‘Marian’ reforms are well attested in the sources. Sallustius wrote that Marius “enrolled soldiers, not according to the classes in the manner of our forefathers, but allowing anyone to volunteer, for the most part the proletariat”.[1] Plutarchus adds that “contrary to law and custom he enlisted many a poor and insignificant man, although former commanders had not accepted such persons”.[2] The reforms were important, but it would be wrong to see them as revolutionary. They were more likely part of a gradual process and a gradual transformation of the Roman army. That process did not end with Marius. The property qualifications were not abolished altogether, not all soldiers were recruited from the proletarii, legions were still impermanent units that were disbanded after a war and issues such as pensions and grants of land to soldiers who retired still had to be decided. In other words, the famous professional standing army of the Roman Empire was still more than 100 years away.

The Jugurthine War

Marius collected his reinforcements and sailed to Utica. Metellus refused to meet him and instructed his legate Rutilius Rufus to transfer command of the African army to his successor. Marius merged the veterans from Metellus’ campaigns with his own reinforcements and subsequently invaded the fertile countryside of Numidia. He had boasted that he would quickly end the war, but his campaign was by no means a walkover. Jugurtha had resorted to guerrilla warfare and frequently conducted raids into territories held by Roman allies. The king and his new ally, the Mauretanian king Bocchus, had split their forces so that they could attack on multiple fronts. But Marius was on his guard, discovered enemy ambushes in time and often defeated attacks by the Numidians, the Moors and their Gaetulian allies. In the vicinity of Cirta, he managed to rout the king’s army. Unfortunately for Marius, these were just minor successes. The enemy remained elusive and the consul did not seem to get any closer to winning the war.

Marius therefore decided to focus on fortified cities and strongholds. If these could be captured, Jugurtha would be deprived of his places of refuge. Perhaps this would lure him into fighting a decisive battle. The consul’s first target was Capsa. At the end of summer, he reached the city and managed to take it by surprise. Marius had created a diversion by sending his legate Aulus Manlius to Laris (or Lares). He pretended to be heading in the same direction, but secretly swung south and reached the river Tanais after five days. It took him three more days to reach Capsa, where he made his camp about two miles from the city. Marius’ army had remained undetected and the inhabitants of Capsa certainly did not expect an attack. They went about their daily business, and that included walking in and out of the city. The consul now ordered his cavalry and the fastest runners among his infantry to attack. The Romans managed to trap many of the inhabitants outside their walls, causing Capsa to surrender. Since the ram had not yet touched the wall, Marius was morally required to spare the city, but he burned it to the ground anyway and killed all the adult Numidians. Sallustius explicitly calls his deed a war crime (facinus contra ius belli).[3] The consul probably did not care: he had taken an important city without losing a single man.

Theatre of the Jugurthine War (source: Ancient World Mapping Center. “À-la-carte”; CC BY 4.0).

The Great Threat from the North

The Romans had suffered painful defeats at the hands of the Cimbri and Teutones, two migrating Germanic tribes, in 113 BCE and 109 BCE. This year, they would suffer another humiliating loss. Their opponents were the Tigurini, a Celtic tribe related to the Helvetii from modern-day Switzerland. The Tigurini had allied themselves with the Cimbri and Teutones and had joined them in their invasion of Gaul some years previously. They seem to have operated quite independently, and this year they clashed with the army of Lucius Cassius Longinus, Marius’ consular colleague.

Theatre of the War against the Cimbri and Teutones (source: Ancient World Mapping Center. “À-la-carte”; CC BY 4.0).

Some Celtic war gear.

Cassius had been praetor in 111 BCE and had been sent to Numidia to summon Jugurtha to Rome. As consul he had been given Gallia Transalpina as his province. When the Tigurini threatened the province, Cassius confronted them and the ensuing battle took place in the territory of the Nitiobriges, probably in the vicinity of modern Agen (Roman Aginnum). This was probably outside the Roman province, which suggests that the consul pursued the Tigurini and was then led into a trap. Details of the battle have not survived, but it seems that the Romans were surrounded and cut to pieces. The consul Cassius was killed and at some point the survivors surrendered. They were allowed to go free after giving hostages and surrendering half of their possessions.

Among those killed was a certain Lucius Calpurnius Piso, who probably served as one of Cassius’ legates. He happened to be the grandfather of Gaius Julius Caesar’s father-in-law. Caesar explicitly mentions this Piso in his Commentaries.[4] He had good reasons to do so: Piso was killed by the Tigurini, and Caesar killed scores of people from this tribe during his own Gallic campaign. He could now present this bloodshed as a form of revenge.

An officer named Gaius Popilius, possibly a tribune or senior centurion, had survived the massacre and had apparently played a role in the negotiations that had been opened at some point during the battle. His actions had saved the lives of countless Romans and Italians, but for some of his countrymen the defeat was just too humiliating. A people’s tribune named Gaius Coelius accused Popilius of treason (maiestas) and wanted to prosecute him. The outcome of the trial in the popular assembly is uncertain, but Coelius was also responsible for introducing important legislation concerning the secret ballot during capital trials (there had been a secret ballot for non-capital trials since 137 BCE). This will be discussed for the next year.


Primary sources

Secondary sources

  • Adrian Goldsworthy, In the name of Rome, p. 135.


[1] The War with Jugurtha 86.

[2] Life of Marius 9.

[3] The War With Jugurtha 91.

[4] De Bello Gallico, Book 1.12.


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