THE RISE OF ROME 85 of the second there had been a war between Rome and the Gauls of Northern Italy, with the result that Rome had planted colonies in Gallic territory. Hannibal's plan of the war rested on the natural belief that initial pianof victories on his part would lead to a revolt of Campaign, large numbers of the Italians against the Roman supremacy. He counted on the active co-operation of the Gauls, and he trusted to Spain as the basis from which reinforcements should be drawn. He probably knew that the jealousy of the oligarchical families at Carthage would make it vain to anticipate from Africa energetic support for his own operations. The Romans, on the other hand, expected the war to be waged mainly in Sicily, on the seas, and in Africa ; but they had also realised that for aggressive purposes Spain, not Africa, was the Carthaginian basis. The Roman fleet was now so powerful, however, that there was no fear of a serious invasion of Italy by sea ; and an invasion by land, involving the march of an army past the Pyrenees, through the wild tribes inhabiting the south of France, and across 'the Alps, did not at first sight seem alarming. But the genius of Hannibal surmounted these tremendous difficulties. The Roman consul was starting with an army for Spain by sea when he learnt that Hannibal was already past the Pyrenees. He endeavoured unsuccessfully to check the Hannibal advance of the Carthaginian army on the Rhone ; crosses the but he still counted on the force becoming ^P 8 " disorganised in the passage of the Alps, and despatched his main army to Spain, though he himself returned to Italy, hoping to crush Hannibal when he came down into the Gallic plain. In fact, when Hannibal pierced into Italy, he had with him little more than 25,000 men out of the army with which he had started. Nevertheless, he inflicted a severe defeat Battles of on the Romans at the Trebia. The Romans found the Trebia, themselves obliged to face an active and brilliant 218BC - general on Italian territory, and were forced to conduct a war on defensive lines. In the next year Hannibal penetrated into Etruria, and
