Titus Livius (Livy), The History of Rome, Book 1
Benjamin Oliver Foster, Ph.D., Ed.

14. Some years later the kinsmen of King Tatius maltreated the envoys of the Laurentians, and when their fellow-citizens sought redress under the law of nations, Titus yielded to his partiality for his relations and to their entreaties. [2] In consequence of this he drew down their punishment upon himself, for at Lavinium, whither he had gone to the annual sacrifice, a mob came together and killed him. [3] This act is said to have awakened less resentment than was proper in Romulus, whether owing to the disloyalty that attends a divided rule, or because he thought Tatius had been not unjustly slain. He therefore declined to go to war; but yet, in order that he might atone for the insults to the envoys and the murder of the king, he caused the covenant between Rome and Lavinium to be renewed.

[4] Thus with the Laurentians peace was preserved against all expectation; but another war broke out, much nearer, and indeed almost at the city gates. The men of Fidenae, perceiving the growth of a power which they thought too near themselves for [p. 53]safety, did not wait till its promised strength should¹ be realized, but began war themselves. Arming the young men, they sent them to ravage the land between the City and Fidenae. [5] Thence they turned to the left —for the Tiber stopped them on the right —and by their devastations struck terror into the farmers, whose sudden stampede from the fields into the City brought the first tidings of war. [6] Romulus led forth his army on the instant, for delay was impossible with the enemy so near, and pitched his camp a mile from Fidenae. Leaving there a small guard, he marched out with all his forces. [7] A part of his men he ordered to lie in ambush, on this side and on that, where thick underbrush afforded cover; advancing with the greater part of the infantry and all the cavalry, and delivering a disorderly and provoking attack, in which the horsemen galloped almost up to the gates, he accomplished his purpose of drawing out the enemy. For the flight, too, which had next to be feigned, the cavalry engagement afforded a favourable pretext. [8] And when not only the cavalry began to waver, as if undecided whether to fight or run, but the infantry also fell back, the city gates were quickly thronged by the enemy, who poured out and hurled themselves against the Roman line, and in the ardour of attack and pursuit were drawn on to the place of ambuscade. [9] There the Romans suddenly sprang out and assailed the enemy's flanks, while, to add to their terror, the standards of the detachment which had been left on guard were seen advancing from the camp; thus threatened by so many dangers the men of Fidenae scarcely afforded time for Romulus and those whom they had seen riding off with him to wheel about, before they [p. 55]broke and ran, and in far greater disorder than that² of the pretended fugitives whom they had just been chasing —for [10] the flight was a real one this time — sought to regain the town. [11] But the Fidenates did not escape their foes; the Romans followed close upon their heels, and before the gates could be shut burst into the city, as though they both formed but a single army.