Authors: Ernle Bradford
Hannibal had at first encamped slightly to the south of the hill of Cannae. On hearing of the Romans’ approach, he moved his troops across the Aufidus and set up a new camp on the west bank. Since the land on that side was even flatter and more suitable for cavalry, he hoped to be able to engage them where the superiority of his horsemen could more easily make itself felt. On the day that the two armies first came in sight of one another Aemilius Paulus was in command and, recognising that the land ahead clearly favoured a cavalry action, he cautioned Terentius Varro that the legions would enjoy more advantage if they moved up to hillier ground. Varro did not agree and on the next day, having the command, he decided to take the legions down to the Aufidus and face Hannibal across the plain. Although Polybius puts the speech to the troops into the mouth of Paulus, there can be no doubt that the following words reflected Varro’s opinion:
…It would be a strange or rather indeed impossible thing, that after meeting your enemies on equal terms in so many separate skirmishes and in most cases being victorious, now when you confront them with your united forces and outnumber them by more than two to one you should be beaten.
Varro was well aware that this new army had been sent out to gain a great victory and to rid Rome of the Carthaginian once and for all. He had no use for any tactics that savoured of Fabius ‘the Delayer’, and talk about moving to hilly ground only made him the more determined to come down into the plain.
So the whole Roman army moved to the west bank of the Aufidus where they established their main camp, facing Hannibal’s troops and about two miles away from them to the north. At the same time part of the army was sent across a ford to establish a smaller secondary camp on the eastern bank of the river. While the Romans were in column of route they were attacked by some of Hannibal’s Numidian light horsemen and suffered a few casualties. This encounter was of no great consequence and the Numidians withdrew when they found themselves up against the heavy Roman cavalry reinforced by the legions. If anything, the Romans had the advantage in this first clash and a certain optimism must have been engendered by it, ‘the Carthaginians not having had the success that they had hoped’. On the following day Aemilius Paulus resumed the command and ‘seeing that the Carthaginians would soon have to shift their camp in order to obtain supplies, kept quiet, after securing his two camps by covering forces’. In this he was quite correct, for by moving across the river Hannibal was now on the far side from Cannae and his supplies. He again sent out the Numidians, with orders to harass the Roman watering parties who were busy working out of the smaller camp on the east bank of the river. Roman tempers became frayed as they saw this far camp besieged by flying squads of horsemen and their water supplies denied them.
It was June. The hot summer had set in, water was all important, and the plain around the Aufidus river was beginning to shake with heat. During that night, or early on the following day, the wind shifted into the south and a sirocco (known locally as a Volturnus) began to blow. Puffing up lazily along the Adriatic, and reaching the two encamped armies over mile upon mile of Italy, from the Ionian Sea and the distant Gulf of Taranto, the humid air brought up the dust of the land with it. A debilitating wind, the sirocco lays a film of dust and moisture on even the unencumbered traveller; the new legions, scarcely used to living with arms and armour, unlike Hannibal’s veterans, sweated as the sun came up. Already it was the pitiless ‘lion sun’ of summer and men would have to contend not only with their enemy but with the greatest enemy of all in southern lands, the noonday heat. On that day, the fourth since the armies had come in sight of one another, it was Terentius Varro’s turn to take the command, ‘and just after sunrise he began to move his forces out of both camps’.
He crossed the river with the main part of the army and joined the smaller camp on the east bank. His reasons for doing so were not investigated by early historians, and yet this movement, which determined the site of the battlefield, is surely important. First of all, the second camp had been primarily established to provide a watering place from a convenient ford, and water would be crucial on a summer day. Secondly, by moving over to the side on which rose the hill of Cannae and its granary buildings, Varro was threatening Hannibal’s food supplies. Thirdly, by being the first to move and to have his forces drawn up in line before the heat of the day began, he may have hoped to surprise Hannibal and, anticipating that the latter’s forces would naturally move to meet the Romans, to catch the Carthaginian army while still in disarray after their river crossing. Fourthly, the land on the eastern bank of the Aufidus, though flat enough, possessed a number of undulations and irregularities which would make it more difficult for the cavalry. Varro did not act with precipitate stupidity. (Some historians have placed the battle of Cannae on the west bank of the river, but a careful study shows that this was not so. In any case, if it had taken place on the western bank it would undoubtedly have been called after the river Aufidus. It was the ship-like hill of Cannae that dominated the scene and gave the battle its name.)
As soon as he saw the Romans beginning to move on that steamy day, Hannibal sent his light-armed troops—the slingers and pikemen—across the river. He knew who was in command of the Roman army and he knew, even before the main body of the opposing troops began to debouch towards the river, that at long last he had brought the main body of Roman arms to battle. Ever since Lake Trasimene he had waited for this moment, and the year of waiting—foiled always by the temperate intelligence of Fabius—could now perhaps be brought to the necessary and dynamic conclusion.
The Romans were drawing up in battle formation as Hannibal and the body of his army crossed the Aufidus in two separate places and went into the tactical pattern that he had designated for them. If he had been fighting on the west bank of the Aufidus he would have put his light Numidian horse on his left flank where their mobility could be put to the best use, and his heavy cavalry on his right nearest the river where it would not matter so much that their charge would be restricted. As it was, drawing up his army in the land below the hill of Cannae, he put the Numidians on his right flank where they could again make use of the open country, and the heavy brigade, consisting of Spaniards and Gauls, on his left next to the winding river. They would be facing the cavalry of the Roman right wing and it was his hope that their greater skill and numerical superiority would enable him to crush the Romans on the river side. Next to them he stationed half of his African veterans, heavy infantry armed largely with equipment taken from the Romans at Trasimene. In the centre, where he himself commanded, he placed the bulk of his troops, the Spaniards and Gauls, with the other half of his Africans on their right, and beyond them the Numidian horse. Polybius comments that the Africans ‘were armed in the Roman fashion. The shields of the Spaniards and the Celts were very similar, but their swords were entirely different, those of the Spaniards thrusting with a deadly effect as they cut, but the Gaulish being only able to slash and requiring a long sweep to do so. As they were drawn up in alternate companies, the Gauls naked and the Spaniards in short tunics bordered with purple, their national dress, they presented a strange and impressive appearance.’
Hannibal’s brother Mago was with him in command of the centre, Hasdrubal, Hannibal’s staff officer, commanded the Carthaginian left, and Hanno the right, with the great cavalry commander Maharbal leading the Numidian horse. Meanwhile the largest army that Rome had yet fielded was drawn up against him in conventional manner with cavalry on each wing, the allied horse on the left facing the Numidians and the Romans on the right, next to the river, facing Hannibal’s heavy horse. In the centre were the legions, line upon line of them: ‘the maniples closer together than was formerly the usage and making the depth of each many times exceed its front.’ It was hoped that, as on many another battlefield, the armoured weight of the disciplined legionaries would punch a hole clean through Hannibal’s centre. Aemilius Paulus, capable but reluctant for this action which he considered ill-advised, commanded the Roman cavalry while Terentius Varro led the allied cavalry. Geminus Servilius, the consul of the previous year, commanded the Roman centre composed of the legions.
At that moment, as both armies faced one another and the sheer weight and numerical superiority of the Romans was plain to every eye, there must have been a moment of trepidation among the Carthaginians, and among the small group of staff officers surrounding Hannibal. Plutarch relates how one of them named Gisgo voiced the thought that lay uppermost in his mind:
‘It is astonishing to see so great a number of men.’
Hannibal sensed his anxiety and decided to turn it in his own way: ‘Yes, Gisgo, you are right, but there is one thing you have not noticed.’
‘What is that, sir?’ asked the puzzled officer.
‘In all that great number of men opposite us there is not a single one named Gisgo!’
The small group burst into laughter, the tension broke, and the ranks of men behind them felt their confidence restored by the laughter of their leaders on the summer air.
By the time that the armies had drawn up in battle array—the light-armed troops, slingers, skirmishers and pikemen, advancing to initiate the opening stages—the sun was high in the sky. As it swung round to the south the Romans had it in their eyes, the Carthaginians at their backs. The sirocco began to blow more strongly as the day advanced, ‘a wind’, as Livy says, ‘that blows clouds of dust over the drought-parched plains’. It lifted over the land behind the Carthaginian lines and blew steadily in the face of the Romans and their allies. When the trampling of thousands of men and horses, the clatter of armour and swords, the neighing of the horses, and the ordered shouts of officers and centurions had subsided, the two armies faced each other in the uneasy half-silence that precedes a storm. To the brazen sound of trumpets the light troops advanced through the dense air to make those first exploratory jabs at one another, like boxers searching for an opening.
As the armies began to move it was noticeable that the Carthaginian centre was drawn forward in a curious crescent-shaped formation, the cusp of this crescent projecting towards the enemy, ‘the line of the flanking companies growing thinner as it was prolonged’. Hannibal was going to open the battle proper with his Spaniards and Gauls, leaving the heavy-armed Africans as reserves on either wing. They formed, as it were, strong rectangles flanking the projecting crescent. Dour and dark, equipped with their Roman arms, the African troops were like shadows on either side of the blood-lusting, war-crying demi-lune that projected beyond them.
The real engagement began with the Spanish and Gallic horse and the Roman heavy cavalry, both of them being constricted by the river. Only a head-on charge could ensue, and the Romans—the armoured knights who were eager to prove their virtue and patriotism in front of the plebeian legionaries—had the disadvantage that, unlike their opposing numbers, they had not lived and fought in the saddle for a number of months, let alone years. ‘Both parties pushed straight ahead,’ writes Livy, ‘and as the horses came to a standstill, packed together in the throng, the riders began to grapple with their enemies and drag them from their seats. They were fighting on foot now, for the most part….’ The Romans, only a week or so out of their winter quarters, and many of them soft from the city, were no match for their enemy: ‘Sharp though the struggle was, it was soon over, and the defeated Roman cavalry turned and fled.’ The heavy cavalry stormed through the gap left by the collapse of the Roman right wing. Consul Aemilius Paulus, who had been in command, escaped unharmed in this savage action and rode to the centre where he put himself at the head of the legionaries ‘cheering on and exhorting his men’. He was of the old Roman stock, conservative but prepared to fight even where he himself would not have given battle. On the Carthaginian right the Numidians had now come into action against the allied Roman horsemen, the Africans using the free scope of ground beyond them to avoid any head-on clash but wheeling about and attacking their enemy in shifts and dips and glides like birds of prey.
Meanwhile the main bodies of the two armies, the sweating infantry, had come into collision. Hannibal, ‘who had been in this part of the field since the commencement of the battle’, regardless as always of his own safety, led on the very troops whom he had doomed to sacrifice. The thin line of Spaniards and Gauls could not hold for very long against the steady, bludgeon-like blows that the dense mass of the advancing legions threw against it. Slowly but surely the cusp of the crescent yielded and fell back, first an indentation, and then a U-shape. The legions, close-packed from the start and without the mobility that their open maniple formation normally gave them, now began to pour in behind one another so that they were like a stream of armour bursting through a collapsing dyke. But on either side of the yielding centre the iron walls of the Africans stood firm. Unlike the legionaries who had headed the attack, and unlike the legionaries who followed them (compressed together, shoulder to shoulder, scarcely able to raise their sword arms), the Africans had so far taken no part in the fighting.
On the Carthaginian right wing the Numidians had triumphed over the Roman allied cavalry, ill-matched as the latter were against the most skilful horsemen in the world, and were now pursuing the enemy as they scattered. Among those who fled was Consul Gaius Terentius Varro, the man whose misplaced confidence had led to this bloody encounter on the field of Cannae. All the while the Roman legions continued to drive in Hannibal’s centre. They had penetrated so far that the African infantry on the wings projected on either side like banks enclosing a moving river of armour. ‘In the thick of the battle Lucius Aemilius Paulus fell as a result of many dreadful wounds….’ Hasdrubal, Hannibal’s staff officer, who was at the head of the Carthaginian heavy cavalry, had meanwhile completely routed the Roman right wing and now swung his horsemen round behind the Roman legions, attacking the allied horse on their left. Already in disarray, or in flight before the Numidians, this thunder of heavy cavalry in their rear completed the collapse of the Roman left wing.