Titus Livius (Livy), The History of Rome, Book 1
Rev. Canon Roberts, Ed.

12. However this may be, the Sabines were in possession of the citadel. And they would not come down from it the next day, though the Roman army was drawn up in battle array over the whole of the ground between the Palatine and the Capitoline hill, until, exasperated at the loss of their citadel and determined to recover it, the Romans mounted to the attack. [2] Advancing before the rest, Mettius Curtius, on the side of the Sabines, and Hostius Hostilius, on the side of the Romans, engaged in single combat. [3] Hostius, fighting on disadvantageous ground, upheld the fortunes of Rome by his intrepid bravery, but at last he fell; the Roman line broke and fled to what was then the gate of the Palatine. [4] Even Romulus was being swept away by the crowd of fugitives, and lifting up his hands to heaven he exclaimed: ‘Jupiter, it was thy omen that I obeyed when I laid here on the Palatine the earliest foundations of the City. Now the Sabines hold its citadel, having bought it by a bribe, and coming thence have seized the valley and are pressing hitherwards in battle. [5] Do thou, Father of gods and men, drive hence our foes, banish terror from Roman hearts, and stay our shameful flight! [6] Here do I vow a temple to thee, ‘Jove the Stayer,’ as a memorial for the generations to come that it is through thy present help that the City has been saved.’ [7] Then, as though he had become aware that his prayer had been heard, he cried, ‘Back, Romans! Jupiter Optimus Maximus bids you stand and renew the battle.’ [8] They stopped as though commanded by a voice from heaven-Romulus dashed up to the foremost line, just as Mettius Curtius had run down from the citadel in front of the Sabines and driven the Romans in headlong flight over the whole of the ground now occupied by the Forum. He was now not far from the gate of the Palatine, and was shouting: ‘We have conquered our faithless hosts, our cowardly foes; now they know that to carry off maidens is a very different thing from fighting with men.’ [9] In the midst of these vaunts Romulus, with a compact body of valiant troops, charged down on him. Mettius happened to be on horseback, so he was the more easily driven back, the Romans followed in pursuit, and, inspired by the courage of their king, the rest of the Roman army routed the Sabines. [10] Mettius, unable to control his horse, maddened by the noise of his pursuers, plunged into a morass. The danger of their general drew off the attention of the Sabines for a moment from the battle; they called out and made signals to encourage him, so, animated to fresh efforts, he succeeded in extricating himself. Thereupon the Romans and Sabines renewed the fighting in the middle of the valley, but the fortune of Rome was in the ascendant.