Titus Livius (Livy), The History of Rome, Book 7
Rev. Canon Roberts, Ed.

9. The consuls for the following year were C. Sulpicius and C. Licinius Calvus. They resumed operations against the Hernici, and invaded their territory, but did not find the enemy in the open. They attacked and captured Ferentinum, a Hernican city; but as they were returning home the Tiburtines closed their gates against them. [2] There had previously been numerous complaints made on both sides, but this last provocation finally decided the Romans, in case the Fetials failed to get redress, to declare war against the Tiburtines. [3] It is generally understood that T. Quinctius Pennus was the Dictator and Ser. Cornelius Maluginensis the Master of the horse. According to Licinius Macer, the Dictator was nominated by the consul Licinius. [4] His colleague, Sulpicius, was anxious to get the elections over before he departed for the war, in the hope of being himself re-elected, if he were on the spot, and Licinius determined to thwart his colleague's self-seeking ambition. [5] Licinius Macer's desire to appropriate the credit of this to his house (the Licinii) lessens the weight of his authority. As I find no mention of this in the older annalists, I am more inclined to believe that it was the prospect of a Gaulish war which was the immediate cause why a Dictator was nominated. [6] At all events it was in this year that the Gauls formed their camp by the Salarian road, three miles from the City at the bridge across the Anio.

In¹ face of this sudden and alarming inroad the Dictator proclaimed a suspension of all business, and made every man who was liable to serve take the military oath. [7] He marched out of the City with an immense army and fixed his camp on this side the Anio. Each side had left the bridge between them intact, as its destruction might have been thought due to fears of an attack. [8] There were frequent skirmishes for the possession of the bridge; as these were indecisive, the question was left unsettled. A Gaul of extraordinary stature strode forward on to the unoccupied bridge, and shouting as loudly as he could, cried: ‘Let the bravest man that Rome possesses come out and fight me, that we two may decide which people is the superior in war.’