After his return to Rome, he quitted his house on the Palatine Mount, and went to live near the market-place, endeavouring to make himself more popular in those parts, where most of the humble and poorer citizens lived. He then brought forward the remainder of his proposed laws, as intending to have them ratified by the popular vote;to support which a vast number of people collected from all quarters. But the senate persuaded Fannius, the consul, to command all persons who were not born Romans to depart the city. A new and unusual proclamation was thereupon made, prohibiting any of the allies or Confederates to appear at Rome during that time. Caius, on the contrary, published an edict, accusing the consul for what he had done, and setting forth to the Confederates, that if they would continue upon the place, they might be assured of his assistance and protection. However, he was not so good as his word; for though he saw one of his own familiar friends and companions dragged to prison by Fannius's officers, he, notwithstanding, passed by without assisting him; either because he was afraid to stand the test of his power, which was already decreased, or because, as he himself reported, he was unwilling to give his enemies an opportunity, which they very much desired, of coming to actual violence and fighting. About that time there happened likewise a difference between him and his fellow-officers upon this occasion. A show of gladiators was to be exhibited before the people in the market-place, and most of the magistrates erected scaffolds round about, with an intention of letting them for advantage. Caius commanded them to take down their scaffolds, that the poor people might see the sport without paying anything. But nobody obeying these orders of his, he gathered together a body of labourers, who worked for him, and overthrew all the scaffolds the very night before the contest was to take place. So that by the next morning the market-place was cleared, and the common people had an opportunity of seeing the pastime. In this, the populace thought he had acted the part of a man; but he much disobliged the tribunes his colleagues, who regarded it as a piece of violent and presumptuous interference.
This was thought to be the chief reason that he failed of being the third time elected tribune; not but that he had the most votes, but because his, colleagues out of revenge caused false returns to be made. But as to this matter there was a controversy. Certain it is, he very much resented this repulse, and behaved with unusual arrogance towards some of his adversaries who were joyful at his defeat, telling them that all this was but a false sardonic mirth, as they little knew how much his actions threw them into obscurity.
As soon as Opimius also was chosen consul, they presently cancelled several of Caius's laws, and especially called in question his proceedings at Carthage, omitting nothing that was likely to irritate him, that from some effect of his passion they might find out a tolerable pretence to put him to death. Caius at first bore these things very patiently; but afterwards, at the instigation of his friends, especially Fulvius, he resolved to put himself at the head of a body of supporters, to oppose the consul by force. They say also that on this occasion his mother, Cornelia, joined in the sedition, and assisted him by sending privately several strangers into Rome, under pretence as if they came to be hired there for harvest-men;for that intimations of this are given in her letters to him. However, it is confidently affirmed by others that Cornelia did not in the least approve of these actions.
When the day came in which Opimius designed to abrogate the laws of Caius, both parties met very early at the capitol; and the consul having performed all the rites usual in their sacrifices, one Quintus Antyllius, an attendant on the consul, carrying out the entrails of the victim, spoke to Fulvius, and his friends who stood about him, "Ye factious citizens, make way for honest men." Some report that, besides this provoking language, he extended his naked arm towards them, as a piece of scorn and contempt. Upon this he was presently killed with the strong stiles which are commonly used in writing, though some say that on this occasion they had been manufactured for this purpose only. This murder caused a sudden consternation in the whole assembly, and the heads of each faction had their different sentiments about it. As for Caius, he was much grieved, and severely reprimanded his own party, because they had given their adversaries a reasonable pretence to proceed against them, which they had so long hoped for. Opimius, immediately seizing the occasion thus offered, was in great delight, and urged the people to revenge; but there happening a great shower of rain on a sudden, it put an end to the business of that day.