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

39. next day the dictator sought the auspices afresh and carried the law through. then, setting out with the legions which had recently been recruited on account of [2??] the fear occasioned by the army's march through the Ciminian Forest, he came to the vicinity of Longula,¹ and taking over from Marcius the consul his veteran troops, marched out and offered battle, which the enemy on their part seemed willing to accept. [3] but while the two armies stood armed and ready for the conflict, which neither cared to begin, night overtook them. [4] for some time after that they remained quietly in the camps [p. 317]they had established near one another, neither lacking² confidence in themselves nor yet making light of their adversaries. [5] meanwhile the Etruscans, employing a lex sacrata,³ had raised an army in which each man had chosen his comrade, and joined battle, with greater forces, and at the same time with greater valour, than ever before. [6] The field was contested with such rivalry of rage that neither side discharged a missile. The battle began with swords, and, furious at the outset, waxed hotter as the struggle continued, for the victory was long undecided. it seemed as though the Romans were contending, not with the so oft defeated Etruscans, but with some new race. [7] no sign of flight was visible in any quarter. as the front —rankers fell, the second line moved up to replace the first, that the standards might not want defenders. [8] after that the last reserves were called upon; and to such extremity of distress and danger did the Romans come that their cavalry dismounted, and made their way over arms and over bodies to the front ranks of the infantry. like a fresh line springing up amongst the exhausted combatants, they wrought havoc in the companies of the Etruscans. [9] then the rest of the soldiers, following up their charge, despite of weariness, at last broke through the enemy's ranks. [10] at this their stubbornness began to be overcome, and certain companies to face about; and when these had once turned tail, the rest likewise took to flight. [11] that [p. 319]day for the first time broke the might of the⁴ Etruscans, which had long flourished in prosperity. their strength was cut off in the battle, and their camp was taken and plundered in the same attack.