The arrival of the Cimbri in Gaul in 109 BC and their complete defeat of Marcus Junius Silanus had crippled Roman prestige, resulted in unrest among the Celtic tribes recently conquered by the Romans in southern Gaul.
In 107 the consul Lucius Cassius Longinus was completely defeated by the Tigurini, and the senior surviving officer (one Gaius Popillius, son of the consul of 132) had saved what was left only by surrendering half the baggage and suffering the humiliation of having his army "march under the yoke".
The next year, 106 BC, another consul, Quintus Servilius Caepio, marched to Gaul with another new army to salvage the situation.
There, he captured the town community of Tolosa (modern day Toulouse), where he discovered a great treasure cache called the Gold of Tolosa, believed to be stolen from the Greek temple of Delphi.
It was stolen when being transported to Massilia (modern day Marseille), with Caepio suspected of having organised the theft.
While Caepio was prorogued into the next year, the new consul for 105 BC Gnaeus Mallius Maximus, was also assigned to southern Gaul with another army.
Caepio's disdain for Mallius – a new man like Marius and hunger for glory – made it impossible for them to cooperate.

The Cimbri and the Teutones (both migrating Germanic tribes) appeared on the Rhône, and while Caepio was on the west bank he refused to come to the aid of Mallius on the left.
The Senate was unable to induce Caepio in cooperate with Mallius, which proved both generals' undoing.
The Cimbri, at the Battle of Arausio, overwhelmed and overran Caepio's legions with massively overwhelming numbers.
Caepio's routed men crashed into Mallius' troops, which led to both armies being pinned against the River Rhône and annihilated by the numerically dominant Cimbrian warriors.

The losses in the preceding decade had been bad enough, but this defeat, apparently caused by the arrogance of the nobility and its refusal to co-operate with talented non-nobles, thoroughly discredited the aristocracy's management of foreign threats.
Not only had huge numbers of Romans lost their lives but Italy itself was now exposed to invasion from barbarian hordes.

The Republic, altogether lacking many generals who had recently in fact concluded successfully any recent military campaigns, took the illegal step of electing Marius in absentia for a second consulship in three years.
While his election was not unprecedented, as Quintus Fabius Maximus had been elected for consecutive consulships and it was not unheard of for consuls to be elected in absentia, it certainly was not with recent precedent.
Yet, since the Assembly had the ability to overturn any law, it simply set aside the requirements and made Marius consul.
The arrival of the Cimbri in Gaul in 109 BC and their complete defeat of Marcus Junius Silanus had crippled Roman prestige, resulted in unrest among the Celtic tribes recently conquered by the Romans in southern Gaul. In 107 the consul Lucius Cassius Longinus was completely defeated by the Tigurini, and the senior surviving officer (one Gaius Popillius, son of the consul of 132) had saved what was left only by surrendering half the baggage and suffering the humiliation of having his army "march under the yoke". The next year, 106 BC, another consul, Quintus Servilius Caepio, marched to Gaul with another new army to salvage the situation. There, he captured the town community of Tolosa (modern day Toulouse), where he discovered a great treasure cache called the Gold of Tolosa, believed to be stolen from the Greek temple of Delphi. It was stolen when being transported to Massilia (modern day Marseille), with Caepio suspected of having organised the theft. While Caepio was prorogued into the next year, the new consul for 105 BC Gnaeus Mallius Maximus, was also assigned to southern Gaul with another army. Caepio's disdain for Mallius – a new man like Marius and hunger for glory – made it impossible for them to cooperate.
The Cimbri and the Teutones (both migrating Germanic tribes) appeared on the Rhône, and while Caepio was on the west bank he refused to come to the aid of Mallius on the left. The Senate was unable to induce Caepio in cooperate with Mallius, which proved both generals' undoing. The Cimbri, at the Battle of Arausio, overwhelmed and overran Caepio's legions with massively overwhelming numbers. Caepio's routed men crashed into Mallius' troops, which led to both armies being pinned against the River Rhône and annihilated by the numerically dominant Cimbrian warriors.
The losses in the preceding decade had been bad enough, but this defeat, apparently caused by the arrogance of the nobility and its refusal to co-operate with talented non-nobles, thoroughly discredited the aristocracy's management of foreign threats. Not only had huge numbers of Romans lost their lives but Italy itself was now exposed to invasion from barbarian hordes.
The Republic, altogether lacking many generals who had recently in fact concluded successfully any recent military campaigns, took the illegal step of electing Marius in absentia for a second consulship in three years. While his election was not unprecedented, as Quintus Fabius Maximus had been elected for consecutive consulships and it was not unheard of for consuls to be elected in absentia, it certainly was not with recent precedent. Yet, since the Assembly had the ability to overturn any law, it simply set aside the requirements and made Marius consul.
Gaius Marius