Titus Livius (Livy), The History of Rome, Book 6
Rev. Canon Roberts, Ed.

In this year a serious war broke out, and a still more serious disturbance at home. [2] The war was begun by the Volscians, aided by the revolted Latins and Hernici. The domestic trouble arose in a quarter where it was least to be apprehended, from a man of patrician birth and brilliant reputation —M. Manlius Capitolinus .

[3] Full of pride and presumption, he looked down upon the foremost men with scorn; one in particular he regarded with envious eyes, a man conspicuous for his distinctions and his merits —M. Furius Camillus. [4] He bitterly resented this man's unique position amongst the magistrates and in the affections of the army, and declared that he was now such a superior person that he treated those who had been appointed under the same auspices as himself, not as his colleagues, but as his servants, and yet if any one would form a just judgment he would see that M. Furius could not possibly have rescued his country. ² When it was beleaguered by the enemy had not he, Manlius, saved the [5] Capitol and the Citadel? Camillus attacked the Gauls while they were off their guard, their minds pre-occupied with obtaining the gold and securing peace; he, on the other hand, had driven them off when they were armed for battle and actually capturing the Citadel. Camillus' glory was shared by every man who conquered with him, whereas no mortal man could obviously claim any [6] part in his victory.

With his head full of these notions and being unfortunately a man of headstrong and passionate nature, he found that his influence was not so powerful with the patricians as he thought it ought to be, so he went over to the plebs —the first patrician to do so —and adopted the political [7] methods of their magistrates. He abused the senate and courted the populace and, impelled by the breeze of popular favour more than by conviction or judgment, [8] preferred notoriety to respectability. Not content with the agrarian laws which had hitherto always served the tribunes of the plebs as the material for their agitation, he began to undermine the whole system of credit for he saw that the laws of debt caused more irritation than the others; they not only threatened poverty and disgrace, but they terrified the freeman with the prospect [9] of fetters and imprisonment. And, as a matter of fact, a vast amount of debt had been contracted owing to the expense of building, an expense most ruinous even to the rich.

It became, therefore, a question of arming the government with stronger powers, and the Volscian war, serious in itself but made much more so by the defection of the Latins and Hernici, was put forward [10] as the ostensible reason. It was, however, the revolutionary designs of Manlius that mainly decided the senate to nominate a Dictator. A. Cornelius Cossus was nominated and he named T. Quinctius Capitolinus as his Master of the Horse.