Taking advantage of the Roman Dictator Julius Caesar's absence in Spain, he cultivated the support of the various plebeian collegia, and became enormously popular in the process.
[5] Around the time Caesar returned to Rome in May 45 BC, Pseudo-Marius contacted the former Roman consul Cicero, asking for his help as a defender, presumably concerning a legal case.
[7] With Julius Caesar's assassination on 15 March 44 BC, Pseudo-Marius returned from exile and attempted to set himself up as leader of the city's plebeian masses.
His followers gathered at the Roman Forum and demanded that the altar he had erected be dedicated to Marius, but Antony sent in soldiers to disperse the mob and kill the principal ringleaders.
Caesar would have known from his aunt (Julia, the wife of the famous Gaius Marius, and who died in 68 BC) whether she had a grandson or not, and his hesitancy in getting rid of Pseudo-Marius permanently, as well as his not denouncing the supposed impostor, speaks volumes.
[18] This theory is supported by a passage in Nicolaus of Damascus', Life of Augustus, where he relates that Pseudo-Marius approached the young Gaius Octavius who was accompanied by a number of women from his family.
Some see his execution by Mark Antony without trial as evidence of his non-citizen status,[21] that he was quite likely a wealthy freedman, and that his influence was achieved solely through the use of Marius' name.