In the spring of 218 Hannibal started from Carthágo Nova to invade Italy. His army consisted of 90,000 infantry, 12,000 cavalry, and 37 elephants. His march to the Pyrenees occupied two months, owing to the opposition of the Spanish allies of Rome. Hannibal now sent back a part of his troops, retaining 50,000 infantry and 9,000 cavalry, all veterans. With these he crossed the mountains, and marched along the coast by Narbo (Narbonne) and Nemansus (Nîmes), through the Celtic territory, with little opposition. The last of July found him on the banks of the Rhone, opposite Avenio (Avignon). The Romans were astonished at the rapidity of his movements.

The Consuls of the year were SCIPIO and SEMPRONIUS. The former had been in Northern Italy, leisurely collecting forces to attack Hannibal in Spain; the latter was in Sicily, making preparations to invade Africa. Scipio set sail for Spain, touching at Massilia near the end of June. Learning there for the first time that Hannibal had already left Spain, he hoped to intercept him on the Rhone. The Celtic tribes of the neighborhood were won over to his side. Troops collected from these were stationed along the river, but Scipio's main army remained at Massilia. It was Hannibal's policy to cross the river before Scipio arrived with his troops. He obtained all the boats possible, and constructed numerous rafts to transport his main body of troops. A detachment of soldiers was sent up the river with orders to cross at the first available place, and, returning on the opposite bank, to surprise the Celtic forces in the rear. The plan succeeded. The Celts fled in confusion, and the road to the Alps was opened. Thus Scipio was outgeneralled in the very beginning.

His course now should have been to return to Northern Italy with all his forces, and take every means to check Hannibal there. Instead, he sent most of his troops to Spain under his brother Gnaeus Scipio, and himself, with but a few men, set sail for Pisae.

Meanwhile Hannibal hurried up the valley of the Rhone, across the Isara, through the fertile country of the Allobroges, arriving, in sixteen days from Avenio, at the pass of the first Alpine range (Mont du Chat). Crossing this with some difficulty, owing to the nature of the country and the resistance of the Celts, he hastened on through the country of the Centrónes, along the north bank of the Isara. As he was leaving this river and approaching the pass of the Little St. Bernard, he was again attacked by the Celts, and obliged to make the ascent amidst continual and bloody encounters. After toiling a day and a night, however, the army reached the summit of the pass. Here, on a table-land, his troops were allowed a brief rest.

The hardships of the descent were fully as great, and the fertile valley of the Po was a welcome sight to the half-famished and exhausted soldiers. Here they encamped, in September, and recruited their wearied energies.

This famous march of Hannibal from the Rhone lasted thirty-three days, and cost him 20,000 infantry and 3,000 cavalry.

The Romans were still unprepared to meet Hannibal. One army was in Spain under Gnaeus Scipio; the other in Sicily, on its way to Africa, under the Consul Sempronius. The only troops immediately available were a few soldiers that had been left in the valley of the Po to restrain the Gauls, who had recently shown signs of defection.

Publius Cornelius Scipio, upon his return from Massilia, took command of these. He met Hannibal first in October, 218, near the river Ticinus, a tributary of the Po. A cavalry skirmish followed, in which he was wounded and rescued by his son, a lad of seventeen, afterwards the famous Africanus. The Romans were discomfited, with considerable loss.

They then retreated, crossing the Po at Placentia, and destroying the bridge behind them. Hannibal forded the river farther up, and marched along its right bank until he reached its confluence with the Trebia, opposite Placentia. Here he encamped.

Meanwhile Sempronius, who had been recalled from Sicily, relieved the disabled Scipio.

Early one raw morning in December, 218, the vanguard of the Carthaginians was ordered to cross the Trebia, and, as soon any resistance was met, to retreat. The other troops of Hannibal were drawn up ready to give the enemy a hot reception, if, as he expected, they should pursue his retreating vanguard. Sempronius was caught in the trap, and all his army, except one division of 10,000, was cut to pieces. The survivors took refuge in Placentia and Cremona, where they spent the winter. Sempronius himself escaped to Rome.

The result of TREBIA was the insurrection of all the Celtic tribes in the valley of the Po, who increased Hannibal's army by 60,000 infantry and 4,000 cavalry. While the Carthaginian was wintering near Placentia, the Romans stationed troops to guard the two highways leading north from Rome and ending at Arretium and Ariminum, The Consuls for this year were GAIUS FLAMINIUS and GNAEUS SERVILIUS. The former occupied Arretium, the latter Ariminum. Here they were joined by the troops that had wintered at Placentia.

In the spring, Hannibal, instead of attempting to pursue his march by either of the highways which were fortified, outflanked the Romans by turning aside into Etruria. His route led through a marshy and unhealthy country, and many soldiers perished. Hannibal himself lost an eye from ophthalmia. When he had arrived at Faesulae a report of his course first reached Flaminius, who at once broke camp and endeavored to intercept his enemy. Hannibal, however, had the start, and was now near LAKE TRASIMÉNUS.

Here was a pass with a high hill on one side and the lake on the other. Hannibal, with the flower of his infantry, occupied the hill. His light-armed troops and horsemen were drawn up in concealment on either side.

The Roman column advanced (May, 217), without hesitation, to the unoccupied pass, the thick morning mist completely concealing the position of the enemy. As the Roman vanguard approached the hill, Hannibal gave the signal for attack. The cavalry closed up the entrance to the pass, and at the same time the mist rolled away, revealing the Carthaginian arms on the right and left. It was not a battle, but a mere rout. The main body of the Romans was cut to pieces, with scarcely any resistance, and the Consul himself was killed. Fifteen thousand Romans fell, and as many more were captured. The loss of the Carthaginians was but 1,500, and was confined mostly to the Gallic allies. All Etruria was lost, and Hannibal could march without hindrance upon Rome, whose citizens, expecting the enemy daily, tore down the bridges over the Tiber and prepared for a siege. QUINTUS FABIUS MAXIMUS was appointed Dictator.

Hannibal, however, did not march upon Rome, but turned through Umbria, devastating the country as he went. Crossing the Apennines, he halted on the shores of the Adriatic, in Picénum. After giving his army a rest, he proceeded along the coast into Southern Italy.

The Romans, seeing that the city was not in immediate danger, raised another army, and placed the Dictator in command. Fabius was a man of determination and firmness, well advanced in years. He determined to avoid a pitched battle, but to dog the steps of the enemy, harassing him and cutting off his supplies as far as possible.

Meanwhile Hannibal again crossed the mountains into the heart of Italy to Beneventum, and from there to Capua, the largest Italian city dependent upon Rome. The Dictator followed, condemning his soldiers to the melancholy task of looking on in inaction, while the enemy's cavalry plundered their faithful allies. Finally, Fabius obtained what he considered a favorable opportunity for an attack. Hannibal, disappointed in his expectations that Capua would be friendly to him, and not being prepared to lay siege to the town, had withdrawn towards the Adriatic. Fabius intercepted him near Casilinum, in Campania, on the left bank of the Volturnus. The heights that commanded the right bank of the river were occupied by his main army; and the road itself, which led across the river, was guarded by a strong division of men.

Hannibal, however, ordered his light-armed troops to ascend the heights over the road during the night, driving before them oxen with burning fagots tied to their horns, giving the appearance of an army marching by torchlight. The plan was successful. The Romans abandoned the road and marched for the heights, along which they supposed the enemy were going. Hannibal, with a clear road before him, continued his march with the bulk of his army. The next morning he recalled his light-armed troops, which had been sent on to the hills with the oxen. Their engagement with the Romans had resulted in a severe loss to Fabius.

Hannibal then proceeded, without opposition, in a northeasterly direction, by a very circuitous route. He arrived in Luceria, with much booty and a full money-chest, at harvest time. Near here he encamped in a plain rich in grain and grass for the support of his army.

At Rome the policy of Fabius was severely criticised. His apparent inaction was displeasing to a large party, and he was called Cunctator (the Delayer). At length the assembly voted that his command be shared by one of his lieutenants, Marcus Minucius. The army was divided into two corps; one under Marcus, who intended to attack Hannibal at the first opportunity; the other under Fabius, who still adhered to his former tactics. Marcus made an attack, but paid dearly for his rashness, and his whole corps would have been annihilated had not Fabius come to his assistance and covered his retreat. Hannibal passed the winter of 217-216 unmolested.

The season was spent by the Romans in active preparations for the spring campaign. An army of 80,000 infantry and 6,000 cavalry was raised and put under the command of the Consuls, LUCIUS ÆMILIUS PAULLUS and GAIUS TERENTIUS VARRO. It was decided to test Hannibal's strength once more in open battle. His army was only half as strong as the Roman in infantry, but was much superior in cavalry.

In the early summer of 216 the Consuls concentrated their forces at CANNAE, a hamlet near the mouth of the Aufidus. Early one morning in June the Romans massed their troops on the left bank of the river, with their cavalry on either wing, the right under Paullus, and the left under Varro. The Proconsul Servilius commanded the centre.

The Carthaginians were drawn up in the form of a crescent, flanked by cavalry. Both armies advanced to the attack at the same time. The onset was terrible; but though the Romans fought with a courage increased by the thought that their homes, wives, and children were at stake, they were overwhelmed on all sides. Seventy thousand fell on the field, among whom were Paullus, Servilius, many officers, and eighty men of senatorial rank. This was the most crushing defeat ever experienced by the Romans. All Southern Italy, except the Latin colonies and the Greek cities on the coast, went over to Hannibal.