Titus Livius (Livy), The History of Rome, Book 26
D. Spillan, A.M., M.D., Cyrus Evans, Ed.

10. During this confusion, Fulvius Flaccus entered the city with his troops through the Capuan gate, passed through the midst of the city, and through Carinae, to Esquiliae; and going out thence, pitched his camp between the Esquiline and Colline gates. [2] The plebeian aediles brought a supply of provisions there. The consuls and the senate came to the camp, [p. 1030]and a consultation was held on the state of the republic. It was resolved that the consuls should encamp in the neighbourhood of the Colline and Esquiline gates; that Caius Calpurnius, the city praetor, should have the command of the Capitol and the citadel; and that a full senate should be continually assembled in the forum, in case it should be necessary to consult them amidst such sudden emergencies. [3] Meanwhile, Hannibal advanced his camp to the Anio, three miles from the city, and fixing his position there, he advanced with two thousand horse from the Colline gate as far as the temple of Hercules, and riding up, took as near a view as he could of the walls and site of the city. [4] Flaccus, indignant that he should do this so freely, and so much at his ease, sent out a party of cavalry, with orders to displace and drive back to their camp the cavalry of the enemy. [5] After the fight had begun, the consuls ordered the Numidian deserters who were on the Aventine, to the number of twelve hundred, to march through the midst of the city to the Esquiliae, judging that no troops were better calculated to fight among the hollows, the garden walls, and tombs, or in the enclosed roads which were on all sides. [6] But some persons, seeing them from the citadel and Capitol as they filed off on horseback down the Publician hill, cried out that the Aventine was taken. [7] This circumstance occasioned such confusion and terror, that if the Carthaginian camp had not been without the city, the whole multitude, such was their alarm, would have rushed out. They then fled for refuge into their houses and upon the roofs, where they threw stones and weapons on their own soldiers as they passed along the streets, taking them for enemies. [8] Nor could the tumult be repressed, or the mistake explained, as the streets were thronged with crowds of rustics and cattle, which the sudden alarm had driven into the city. [9] The battle between the cavalry was successful, and the enemy were driven away; and as it was necessary to repress the tumults which were arising in several quarters without any cause, it was resolved that all who had been dictators, consuls, or censors, should be invested with authority till such time as the enemy had retired from the walls. [10] During the remainder of the day and the following night, several tumults arose without any foundation, and were repressed.