and as many horsemen, under the leadership of Mago, Hannibal's youngest brother, suddenly emerged from an ambush in the rear of the Roman army, and fell upon the densely entangled masses. The wings of the army and the rear ranks of the Roman centre were broken up and scattered by this attack, while the first division, 10,000 men strong, in compact array broke through the Carthaginian line, and made a passage for itself obliquely through the midst of the enemy, inflicting great loss on the opposing infantry and more especially on the Gallic insurgents. This brave body, pursued but feebly, thus reached Placentia. The remaining mass was for the most part slaughtered by the elephants and light troops of the enemy in attempting to cross the river: only part of the cavalry and some divisions of infantry were able, by wading through the river, to gain the camp whither the Carthaginians did not follow them, and thus they too reached Placentia[1]. Few battles confer more honour on the Roman soldier than this on the Trebia, and few at the same time furnish graver impeachment of the general in command; although the candid judge will not forget that a commandership in chief expiring on a definite day was an unmilitary institution, and that figs cannot be reaped from thistles. The victory came to be costly even to the victors. Although the loss in the battle fell chiefly on the Celtic insurgents, yet a multitude of the veteran soldiers of Hannibal died afterwards from diseases engendered by that raw and wet winter day, and all the elephants perished except one.
The effect of this first victory of the invading army was, that the national insurrection now spread and assumed shape without hindrance throughout the Celtic territory. The remains of the Roman army of the Po threw themselves into the fortresses of Placentia and Cremona: completely cut off from home, they were obliged to procure their supplies by way of the river. The consul Tiberius Sempronius only escaped, as if by miracle, from being taken prisoner, when with a weak escort of cavalry he went to Rome on account of the elections. Hannibal, who would not hazard the health of his troops by further marches at that inclement season, bivouacked for the winter where he was; and, as a serious attempt on the larger fortresses would have led to no result, contented himself with annoying the enemy by attacks on the river port of Placentia and other minor Roman positions. He employed himself mainly in organizing the Gallic insurrection: more than 60,000 foot soldiers and 4000 horsemen from the Celts are said to have joined his army.
No extraordinary exertions were made in Rome for the campaign of 537. The senate thought, and not unreasonably, that, despite the lost battle, their position was by no means fraught with serious danger. Besides the coast garrisons, which were despatched to Sardinia, Sicily, and Tarentum, and the reinforcements which were sent to Spain, the two new consuls Gaius Flaminius and Gnaeus Servilius obtained only as many men as were necessary to restore the four legions to their full complement; additions were made to the strength of the cavalry alone. The consuls had to protect the northern frontier, and stationed themselves accordingly on the two highways which led from Rome to the north, the western of which at that lime terminated at Arretium, and the eastern at Ariminum; Gaius Flaminius occupied the former, Gnaeus Servilius the latter. There they ordered the troops from the fortresses on the Po to join them, probably by water, and awaited the commencement of the favourable season, when they proposed to occupy in the defensive the passes of the Apennines, and then, taking up the offensive, to descend into the valley of the Po and effect a junction somewhere near Placentia. But Hannibal by no means intended to defend the valley of the Po. He knew Rome better perhaps than the Romans knew it themselves, and was very well aware how decidedly he was the weaker and continued to be so notwithstanding the brilliant battle on the Trebia; he knew too that his ultimate object, the humiliation of Rome, was not to be wrung from the unbending Roman pride either by terror or by surprise, but could only be gained by the actual subjugation of the haughty city. It was clearly apparent that the Italian federation was in political solidity and in military resources infinitely superior to an adversary, who received only precarious and irregular support from home, and who in Italy was dependent for primary aid solely on the vacillating and capricious nation of the Celts; and that the Phoenician foot soldier was, notwithstanding all the pains taken by Hannibal, far inferior in point of tactics to the legionary, had been completely proved by the defensive movements of Scipio and the brilliant retreat of the defeated infantry on the Trebia. From this conviction flowed the two fundamental principles which determined Hannibal's whole method of operations in Italy - viz., that the war should be carried on, in somewhat adventurous fashion, with constant changes in the plan and in the theatre of operations; and that its favourable issue could only be looked for as the result of political and not of military successes - of the gradual loosening and final breaking up of the Italian federation. That mode of carrying on the war was necessary, because the single element which Hannibal had to throw into the scale against so many disadvantages - his military genius - only told with its full weight, when he constantly foiled his opponents by unexpected combinations; he was undone, if the war became stationary. That aim was the aim dictated to him by right policy, because, mighty conqueror though he was in battle, he saw very clearly that on each occasion he vanquished the generals and not the city, and that after each new battle the Romans remained just as superior to the Carthaginians as he was personally superior to the Roman commanders. That Hannibal even at the height of his fortune never deceived himself on this point, is worthier of admiration than his most admired battles.
It was these motives, and not the entreaties of the Gauls that he should spare their country - which would not have influenced him - that induced Hannibal now to forsake, as it were, his newly acquired basis of operations against Italy, and to transfer the scene of war to Italy itself. Before doing so he gave orders that all the prisoners should be brought before him. He ordered the Romans to be separated and loaded with chains as slaves - the statement that Hannibal put to death all the Romans capable of bearing arms, who here and elsewhere fell into his hands, is beyond doubt at least strongly exaggerated. On the other hand, all the Italian allies were released without ransom, and charged to report at home that Hannibal waged war not against Italy, but against Rome; that he promised to every Italian community the restoration of its ancient independence and its ancient boundaries; and that the deliverer was about to follow those whom he had set free, bringing release and revenge. In fact, when the winter ended, he started from the valley of the Po to search for a route through the difficult defiles of the Apennines. Gaius Flaminius, with the Etruscan army, was still for the moment at Arezzo, intending to move from that point towards Lucca in order to protect the vale of the Arno and the passes of the Apennines, so soon as the season should allow. But Hannibal anticipated him. The passage of the Apennines was accomplished without much difficulty, at a point as far west as possible or, in other words, as distant as possible from the enemy; but the marshy low grounds between the Serchio and the Arno were so flooded by the melting of the snow and the spring rains, that the army had to march four days in water, without finding any other dry spot for resting by night than was supplied by piling the baggage or by the sumpter animals that had fallen. The troops underwent unutterable sufferings, particularly the Gallic infantry, which marched behind the Carthaginians along tracks already rendered impassable: they murmured loudly and would undoubtedly have dispersed to a man, had not the Carthaginian cavalry under Mago, which brought up the rear, rendered flight impossible. The horses, assailed by a distemper in their hoofs, fell in heaps; various diseases decimated the soldiers; Hannibal himself lost an eye in consequence of ophthalmia.
But the object was attained. Hannibal encamped at Fiesole, while Gaius Flaminius was still waiting at Arezzo until the roads should become passable that he might blockade them. After the Roman defensive position had thus been turned, the best course for the consul, who might perhaps have been strong enough to defend the mountain passes but certainly was unable now to face Hannibal in the open field, would have been to wait till the second army, which had now become completely superfluous at Ariminum, should arrive. He himself, however, judged otherwise. He was a political party leader, raised to distinction by his efforts to limit the power of the senate; indignant at the government in consequence of the aristocratic intrigues concocted against him during his consulship; carried away, through a doubtless justifiable opposition to their beaten track of partisanship, into a
