As Quaestor he was sent to join Marius in Africa a few months before Cicero was born.

Into his hands, as it happened, not into those of Marius, Jugurtha was surrendered by his father-in-law, Bocchus, who thought thus to curry favor with the Romans.
Thence came those internecine feuds, in which, some twenty-five years later, all Rome was lying butchered.

The cause of quarrelling between these two men, the jealousies which grew in the heart of the elder, from the renewed successes of the younger, are not much to us now; but the condition to which Rome had been brought, when two such men could scramble for the city, and each cut the throats of the relatives, friends, and presumed allies of the other, has to be inquired into by those who would understand what Rome had been, what it was, and what it was necessarily to become.
When Cicero was of an age to begin to think of these things, and had put on the "toga virilis," and girt himself with a sword to fight under the father of Pompey for the power of Rome against the Italian allies who were demanding citizenship, the quarrel was in truth rising to its bitterness.

Marius and Sulla were on the same side in that war.

But Marius had then not only been Consul, but had been six times Consul; and he had beaten the Teutons and the Cimbrians, by whom Romans had feared that all Italy would be occupied.