Titus Livius (Livy), The History of Rome, Book 9
Benjamin Oliver Foster, Ph.D., Ed.

32. while these events were taking place in Samnium, all the peoples of Etruria, except the Arretini, had already armed, and beginning with the siege of Sutrium, a city in alliance with the Romans, and forming as it were the key to Etruria, had set on foot a tremendous war. [2] thither the other consul, Aemilius, came with an army, to relieve the blockade of the allies. as the Romans came up, the Sutrini obligingly brought provisions to their camp, which was formed before the city. [3] The Etruscans spent the first day in deliberating whether to accelerate the war or to draw it out. [4] on the following day, their generals having decided on the swifter plan in preference to the safer, the [p. 287]signal for battle was displayed at sunrise and their¹ men in fighting array marched out upon the field. [5] when this was reported to the consul, he at once commanded the word to be passed round that the men should breakfast, and having recruited their strength with food, should then arm. The order was obeyed; and the consul, seeing them equipped and ready, bade advance the standards beyond the rampart, and drew up his troops a little way off from the enemy. [6] for some time both sides stood fast, observing one another closely, each waiting for the other to give a cheer and begin to fight, and the sun had begun his downward course in the heavens ere a missile was hurled on either side. [7] then the Etruscans, that they might not withdraw without accomplishing their purpose, set up a shout, and with sound of trumpets advanced their ensigns. [8] The Romans were equally prompt to begin the battle. The two armies rushed together with great fury, the enemy having a superiority in numbers, the Romans in bravery. [9] Victory hung in the balance and many perished on both sides, including all the bravest, and the event was not decided until the Roman second line came up with undiminished vigour to relieve their exhausted comrades in the first; and the Etruscans, whose fighting line was supported by no fresh reserves, all fell in front of their standards and around them. [10] there would never in any battle have been more bloodshed or less running away, but when the Etruscans were resolved to die, the darkness shielded them, so that the victors gave over fighting before the vanquished. [11] The sun had set when the recall was sounded, and in the night both armies retired to their camps.

[p. 289] thereafter there was nothing done that year at² Sutrium worth recording. [12] The enemy had lost their whole first line in a single engagement, and had only their reserves remaining, who barely sufficed to garrison their camp; whilst the Romans had so many wounded that more died of their hurts after the battle than had fallen on the field.