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

12. Be that as it may, the Sabines held the citadel. Next day the Roman army was drawn up, and covered the ground between the Palatine Hill and the Capitoline, but the Sabines would not come down till rage and eagerness to regain the citadel had goaded their enemy into marching up the slope against them. [2] Two champions led the fighting, the Sabine Mettius Curtius on the one side, and the Roman Hostius Hostilius on the other. Hostius held the Romans firm, despite their disadvantage of position, by the reckless courage he displayed in the thick of the fray. [3] But when he fell, the Roman line gave way at once and fled towards the old gate of the Palatine. Romulus himself was swept along in the crowd of the fugitives, till lifting his sword and shield to [4] heaven, he cried, “O Jupiter, it was thy omen that directed me when I laid here on the Palatine the first foundations of my City. The fortress is already bought by a crime and in the possession of the Sabines, whence they are come, sword in hand, across the valley to seek us here. [5] But do thou, father of gods and men, keep them back from this spot at least; deliver the Romans from their terror, and stay their shameful flight! [6] I here vow to thee, Jupiter the Stayer, a temple, to be a [p. 47]memorial to our descendants how the City was saved¹ by thy present help.” [7] Having uttered this prayer he exclaimed, as if he had perceived that it was heard, “Here, Romans, Jupiter Optimus Maximus commands us to stand and renew the fight!” The Romans did stand, as though directed by a voice from Heaven, Romulus himself rushing into the forefront of the battle. [8] Mettius Curtius, on the Sabine side, had led the charge down from the citadel, and driven the Romans in disorder over all that ground which the Forum occupies. He was not now far from the gate of the Palatine, shouting, “We have beaten our faithless hosts, our cowardly enemies! They know now how great is the difference between carrying off maidens and fighting with men!” While he pronounced this boast a band of gallant youths, led on by Romulus, assailed him. [9] It chanced that Mettius was fighting on horseback at the time, and was therefore the more easily put to flight. As he fled, the Romans followed; and the rest of their army, too, fired by the reckless daring of their king, drove the Sabines before them. [10] Mettius plunged into a swamp, his horse becoming unmanageable in the din of the pursuit, and even the Sabines were drawn off from the general engagement by the danger to so great a man. As for Mettius, heartened by the gestures and shouts of his followers and the encouragement of the throng, he made his escape; and the Romans and the Sabines renewed their battle in the valley that lies between the two hills. But the advantage rested with the Romans.