Battle of Manlian Pass The Battle of Manlian Pass took place between Romans under Q . Fulvius Flaccus and Celtiberi in 181 BC . Fulvius had arrived as praetor assigned to the province of Hispania Ulterior in 180 , and continued as proconsul for the following two years . The fullest account of the battle is given by Livy ( 40 . 39 - 40 ) : As his successor was somewhat late in reaching Spain , Fulvius Flaccus led out his army from winter quarters and began to devastate the more distant parts of Celtiberia , where the inhabitants had not come in to surrender . By this action he irritated the natives more than he intimidated them , and secretly collecting a force they beset the Manlian Pass , through which they were tolerably certain that the Romans would march . Gracchus had instructed his colleague , L . Postumius Albinus , who was on his way to Further Spain , to inform Q . Fulvius that he was to bring his army to Tarraco , where he intended to disband the old soldiers , incorporate the reinforcements into the various corps and reorganise the whole army . Fulvius was also informed of the date of his successor ' s arrival which was close at hand . This information compelled Flaccus to abandon his projected operations and withdraw his army hastily from Celtiberia . The barbarians , ignorant of the true reason , and imagining that he had become aware of their rising and secret gathering in arms and was afraid of them , invested the pass all the more closely . When the Roman column entered the pass , the enemy rushed down upon it from both sides . As soon as Flaccus saw this , he allayed the first symptoms of tumult in the column by giving the order through the centurions for every man to stand where he was and get his weapons ready . The packs of the baggage animals were piled up in one place , and partly by his own exertions , partly through his officers , he got the whole force into such fighting order as the time and place required . He reminded his men that they had to deal with those who had twice made their submission and who were impelled by treachery , not by true courage . His soldiers , he told them , would have returned home without distinguishing themselves ; the enemy had given them the chance of a glorious and memorable homecoming . They would carry in triumph through Rome swords reddened with the slaughter of their foes and spoils dripping with their blood . Time did not allow him to say more ; the enemy were upon them and fighting was already begun at the outermost points . Then the two lines closed . 40 . 40 The battle was everywhere a desperate one , but with changing fortunes . The legionaries fought splendidly , nor did the two divisions of allied troops offer a less vigorous resistance . The native auxiliaries confronted by men similarly armed , but somewhat better fighters , could not hold their ground . When the Celtiberi found that their regular order of battle made them no match for the legions , they bore down upon them in wedge - formation , a maneuver which gives them such weight that in whatever direction they carry their attack it cannot be withstood . Even the legions were now thrown into disorder and the Roman line was all but broken . Fulvius , seeing this , galloped up to the legionary cavalry and shouted : " Unless you can come to the rescue it will be all over with this army . " " Say , " they shouted in reply , " what you want done , we shall not be slack in carrying out your orders . " He replied : " Close up your squadrons , cavalry of the two legions , and let your horses go where the enemy wedge is pressing our men . Your charge will have all the greater force if you make it on unbitted horses . " ( We have heard that Roman cavalry have often done that and covered themselves with glory . ) They removed the horses ' bits and charged the wedge in both directions , first forward and then back again , inflicting great slaughter upon the enemy and shivering all their spears . When the wedge on which all their hopes rested was broken up , the Celtiberi so completely lost heart that they gave up almost any attempt at fighting and began to look about for means of escape . When the auxiliary cavalry saw the notable feat of the Roman horse they , too , fired by the courage of the others , and without waiting for orders , spurred their horses against the enemy who was now thoroughly shaken . This proved decisive ; the Celtiberi fled precipitately in all directions , and the Roman commander , watching them as they turned their backs , vowed a temple to Fortuna Equestris and the celebration of solemn Games to Jupiter Optimus Maximus . The Celtiberi , scattered in flight , were cut to pieces all through the pass . It is asserted that 17 , 000 of the enemy were killed on that day , and more than 4000 taken alive , together with 277 military standards and nearly 600 horses . The victorious army remained encamped in the pass . The victory was not without loss ; 472 Roman soldiers , 1019 soldiers of the allies and 3000 native auxiliaries perished on the field . With its former glory thus renewed the victorious army marched to Tarraco . Tiberius Sempronius , who had landed two days before , went to meet Fulvius and congratulated him upon his successful conduct of affairs .