But later on the Romans, elated by the good fortune they had already enjoyed, were with one accord eager to do battle with the whole Gothic army and thought that they should make war in the open field. Belisarius, however, considering that the difference in size of the two armies was still very great, continued to be reluctant to risk a decisive battle with his whole army; and so he busied himself still more with his sallies and kept planning them against the enemy. But when at last he yielded his point because of the abuse heaped upon him by the army and the Romans in general, though he was willing to fight with the whole army, yet nevertheless he wished to open the engagement by a sudden sally. And many times he was frustrated when he was on the point of doing this, and was compelled to put off the attack to the following day, because he found to his surprise that the enemy had been previously informed by deserters as to what was to be done and were unexpectedly ready for him. For this reason, then, he was now willing to fight a decisive battle even in the open field, and the barbarians gladly came forth for the encounter. And when both sides had been made ready for the conflict as well as might be, Belisarius gathered his whole army and exhorted them as follows:

"It is not because I detected any cowardice on your part, fellow-soldiers, nor because I was terrified at the strength of the enemy, that I have shrunk from the engagement with them, but I saw that while we were carrying on the war by making sudden sallies matters stood well with us, and consequently I thought that we ought to adhere permanently to the tactics which were responsible for our success. For I think that when one's present affairs are going to one's satisfaction, it is inexpedient to change to another course of action. But since I see that you are eager for this danger, I am filled with confidence and shall never oppose your ardour. For I know that the greatest factor in the decision of war is always the attitude of the fighting men, and it is generally by their enthusiasm that successes are won. Now, therefore, the fact that a few men drawn up for battle with valour on their side are able to overcome a multitude of the enemy, is well known by every man of you, not by hearsay, but by daily experience of fighting. And it will rest with you not to bring shame upon the former glories of my career as general, nor upon the hope which this enthusiasm of yours inspires. For the whole of what has already been accomplished by us in this war must of necessity be judged in accordance with the issue of the present day. And I see that the present moment is also in our favour, for it will, in all probability, make it easier for us to gain the mastery over the enemy, because their spirit has been enslaved by what has gone before. For when men have often met with misfortune, their hearts are no longer wont to thrill even slightly with manly valour. And let no one of you spare horse or bow or any weapon. For I will immediately provide you with others in place of all that are destroyed in the battle."After speaking these words of exhortation, Belisarius led out his army through the small Pincian Gate and the Salarian Gate, and commanded some few men to go through the Aurelian Gate into the Plain of Nero. These he put under the command of Valentinus, a commander of a cavalry detachment, and he directed him not to begin any fighting, or to go too close to the camp of the enemy, but constantly to give the appearance of being about to attack immediately, so that none of the enemy in that quarter might be able to cross the neighbouring bridge and come to the assistance of the soldiers from the other camps. For since, as I have previously stated,[138] the barbarians encamped in the Plain of Nero were many, it seemed to him sufficient if these should all be prevented from taking part in the engagement and be kept separated from the rest of the army. And when some of the Roman populace took up arms and followed as volunteers, he would not allow them to be drawn up for battle along with the regular troops, fearing lest, when they came to actual fighting, they should become terrified at the danger and throw the entire army into confusion, since they were labouring men and altogether unpractised in war. But outside the Pancratian Gate, which is beyond the Tiber River, he ordered them to form a phalanx and remain quiet until he himself should give the signal, reasoning, as actually proved to be the case, that if the enemy in the Plain of Nero should see both them and the men under Valentinus, they would never dare leave their camp and enter battle with the rest of the Gothic army against his own forces. And he considered it a stroke of good luck and a very important advantage that such a large number of men should be kept apart from the army of his opponents.Such being the situation, he wished on that day to engage in a cavalry battle only; and indeed most of the regular infantry were now unwilling to remain in their accustomed condition, but, since they had captured horses as booty from the enemy and had become not unpractised in horsemanship, they were now mounted. And since the infantry were few in number and unable even to make a phalanx of any consequence, and had never had the courage to engage with the barbarians, but always turned to flight at the first onset, he considered it unsafe to draw them up at a distance from the fortifications, but thought it best that they should remain in position where they were, close by the moat, his purpose being that, if it should so happen that the Roman horsemen were routed, they should be able to receive the fugitives and, as a fresh body of men, help them to ward off the enemy.But there were two men among his bodyguards, a certain Principius, who was a man of note and a Pisidian by birth, and Tarmutus, an Isaurian, brother of Ennes who was commander of the Isaurians. These men came before Belisarius and spoke as follows: "Most excellent of generals, we beg you neither to decide that your army, small as it is and about to fight with many tens of thousands of barbarians, be cut off from the phalanx of the infantry, nor to think that one ought to treat with contumely the infantry of the Romans, by means of which, as we hear, the power of the ancient Romans was brought to its present greatness. For if it so happens that they have done nothing of consequence in this war, this is no evidence of the cowardice of the soldiers, but it is the commanders of the infantry who would justly bear the blame, for they alone ride on horseback in the battle-line and are not willing to consider the fortunes of war as shared by all, but as a general thing each one of them by himself takes to flight before the struggle begins. But do you keep all the commanders of infantry, since you see that they have become cavalry and that they are quite unwilling to take their stand beside their subordinates, and include them with the rest of the cavalry and so enter this battle, but permit us to lead the infantry into the combat. For since we also are unmounted, as are these troops, we shall do our part in helping them to support the attack of the multitude of barbarians, full of hope that we shall inflict upon the enemy whatever chastisement God shall permit."

When Belisarius heard this request, at first he did not assent to it; for he was exceedingly fond of these two men, who were fighters of marked excellence, and he was unwilling to have a small body of infantry take such a risk. But finally, overborne by the eagerness of the men, he consented to leave only a small number of their soldiers, in company with the Roman populace, to man the gates and the battlement along the top of the wall where the engines of war were, and to put the rest under command of Principius and Tarmutus, ordering them to take position in the rear in regular formation. His purpose in this was, in the first place, to keep these troops from throwing the rest of the army into confusion if they themselves should become panic-stricken at the danger, and, in the second place, in case any division of the cavalry should be routed at any time, to prevent the retreat from extending to an indefinite distance, but to allow the cavalry simply to fall back upon the infantry and make it possible for them, with the infantry's help, to ward off the pursuers.