CANNAE, an ancient village of Italy, near the river Aufidus, situated on a hill above the right bank, 4m. S.W. from its mouth, and about 6m. below Canusium (q.v.) . It is celebrated for the disastrous defeat which the Romans received there from Hannibal in B.C. In later times the place became a municipium, and un important Roman remains still exist upon the hill known as Monte di Canne. In the middle ages it became a bishopric, but was destroyed in 1276.
There has been considerable discussion as to whether the battle took place on the right or the left bank of the Aufidus, and above or below Cannae; but Kromayer's careful study both of the an cient authorities and of the ground leaves no room for further doubt. According to him, the battlefield is to be sought in the low ground below the village, and on the right bank of the river, which may well have changed its course to some slight extent, where it would seem neither side can have derived any appre ciable advantage from the terrain.
After the operations round Gerunium (see CALLICULA) the Roman and Carthaginian armies lay opposite to one another there until the beginning of the summer of 216 B.C., when Hannibal took the Roman generals by surprise by a rapid march to Can nae, where he seized the Roman stores of provisions, which had been gathered from the neighbourhood of Canusium and were concentrated there; he then encamped on the high ground above the river valley, to the south-west of the village. He probably took the easier and shorter route by Arpi, a distance of some 65m., in as much as that followed later by the Via Traiana is longer and more hilly. The Roman forces followed, but kept on the sea ward side of him, so as to be able to obtain supplies with greater ease. They fought a successful skirmish with his cavalry and light troops between Salapia and Aufidena, after which the consuls, Aemilius Paullus and Terentius Varro, who were in command of the Roman army reached the left bank of the Aufidus. Here they encamped in the plain, throwing a third of their troops onto the right bank of the river, which presented no great obstacle, and establishing a smaller camp there. Hannibal then, in order to persuade his enemy to accept battle, led the bulk of his troops over to the left bank of the river ; but the offer was refused. Varro in his turn offered battle on the right bank, and Hannibal accepted the challenge. The Romans now faced south, with their right wing resting on the river, and the sea about 3m. in their rear. They had adopted an exceptionally deep formation, each maniple having a front of only six men and a depth of 24, which, as we shall see had its bearing on the sequel.
Hannibal, who had only about 40,000 infantry to oppose to the 70,000 Roman foot, placed the Gauls and Spaniards (about 2 5,000 men in all) in the centre, in a crescent shaped forma tion, the units in the middle being heavier and pushed farther forward, while the sides were more lightly held by units in echelon, an arrangement which gave the necessary connection with the 7,000 Libyan heavy infantry who were placed on the wings. The whole formation was of course concealed from the Romans by a screen of light troops, about 8,000 in number. The result of these cleverly concealed dispositions was to leave the Roman wings entirely in the air, so that when they found that there were no troops in front of them it was inevitable that they should ad vance too far and lose touch with their centre. The latter, on the other hand, was at once heavily engaged with Hannibal's Gauls and Spaniards, and, despite their desperate resistance, was at first successful. Hannibal, it is true, had so disposed his line that his centre instead of losing touch as it gave ground, was driven closer together, and so at first actually became stronger ; but after the rectilinear position was reached from which the original advance had been made, this advantage became less ; and when it gave way still further, the day seemed to be lost. Indeed it can only have been then that the Roman troops that escaped the slaughter of Cannae managed to break through the Carthaginian line. This, was, however, the moment for which Hannibal had been waiting. As soon as the shortened Roman front pressed so far forward that the Libyan heavy troops could fall on their flanks, the lat ter, supported by the light troops, attacked the legions on the wings, and prevented them from joining in the break through in the centre. The Roman forces were thus partially encircled, and their discomfiture was completed by Hasdrubal's cavalry (about 10,000 men in all) who, after routing in turn both the Roman cavalry wings, attacked them in the rear. Hannibal, who had taken his own place in the centre, must before this have suc ceeded in stopping the rout and restoring his front at this point. The Romans were, however, still superior in numbers, and it was only owing to the lack of capacity of independent manoeuvre of the individual units that they were unable to prevent them selves from being surrounded in the first instance ; while the exceptional narrowness of front and the great depth in which the Roman legions had been drawn up for battle rendered it possible for Hannibal to surround them with a ring of troops through which they were, in the state of disorder into which they had fallen, quite unable to force a way, and were therefore cut down almost to a man. The 20,000 odd men who had broken through the Carthaginian centre were unable to effect a diversion, and when they saw their comrades surrounded, followed the example of those who had escaped at Trebia and Trasimenus, and marched to Canusium, the modern Canosa. Hannibal preferred not to besiege them there (an operation which might have taken him months) and instead of this marched through Apulia and Samnium to Capua, most of the towns through which he passed with his victorious army declaring themselves in his favour. The Io,000 Romans who were left in the main camp had nothing left but to surrender.
This was the worst defeat that the Romans had suffered at the hands of Hannibal; and yet his victory which gained him the practical annihilation of the Roman army may be said at one time to have hung upon a hair. The Roman generals never gave him another opportunity of a pitched battle, and while they did not give up operations in the open, they tried to wear down Han nibal's strength gradually by operation against him not with large armies, but with a number of smaller forces generally com posed of a couple of legions apiece. The character of the war fare was thus completely altered. This and the fact that Polybius' narrative is only fragmentary from this point onwards explain the impossibility of following the operations of 216-207 in such detail as before.
The similarity of the tactics of Hannibal and of the result of the battle to that of the Trebia is striking; in both, the defeat of the Roman cavalry rendered it possible to outflank and conse quently surround their infantry, while in both cases (and at Trasi menus also) the Roman centre was able to break through in con siderable force, but without being able, or even attempting, to redeem the fortunes of the day.
See J. Kromayer, Antike Schlacht f elder (1912) iii. i. 278 sqq. for an authoritative treatment of the whole question. (T. A.)