Titus Livius (Livy), The History of Rome, Book 30
Frank Gardener Moore, Professor Emeritus in Columbia University, Ed.

8. Scipio, as though the war was already over so far as concerned Syphax and the Carthaginians, was intent upon the siege of Utica and already bringing up his engines to the walls when news of renewed hostilities turned his attention in another direction. [2] And leaving sufficient land and sea forces merely to keep up the appearance of a blockade, he himself at once advanced with the main body of his army against the enemy.¹ [3] At first he established himself upon a hill about four miles from the king's camp. On the following day with his cavalry he [p. 391]went down into the so-called Great Plain,² at the foot³ of that hill, and spent the day in light engagements, advancing against the enemy's outposts and challenging them. [4] And on the next two days by irregular charges, now from one side and now from the other by turns, they accomplished nothing worthy of mention. On the fourth day both went down into battle-line. [5] The Roman placed his principes behind the front line maniples, made up of the hastati, and as reserves the tiarii.⁴ The Italic cavalry he posted on the right wing, on the left the Numidians and Masinissa. [6] Syphax and Hasdrubal opposed the Numidians to the Italic cavalry, the Carthaginians to Masinissa, and then placed the Celtiberians in the centre of the battle-line facing the maniples⁵ of the legions. In this formation they clashed. [7] By the first attack both wings, Numidians and Carthaginians alike, were beaten back at the same time. For neither could the Numidians, most of them rustics, withstand the Roman cavalry, nor could the Carthaginians, who were likewise raw recruits, hold out against Masinissa, a foe to be feared for other reasons and also on account of his recent victory. [8] Stripped of both wings the line of the Celtiberians made a stand because they could see no safety in flight since they did not know the country, and they had no hope of pardon from Scipio since they had come to Africa [p. 393]as mercenaries to attack him in spite of his kind⁶ treatment of them and their tribe. [9] Therefore when the enemy had completely encircled them, falling one above another they were resolute in dying. And while all the enemy were intent upon them Syphax and Hasdrubal took advantage of a considerable interval for flight. Nightfall surprised the victors exhausted by a slaughter outlasting the battle.