Rome prepared for war with her usual firmness and energy. One of the consuls was ordered to pass into Sicily, and thence into Africa; the other to lead an army by sea to Spain, and expel the Carthaginians from that country. But, without waiting the issue of negotiations, Hannibal was in full march to transfer the war into Italy. Sometimes treating with the Celtiberian or Gaulish hordes to obtain a passage through their territory, sometimes intimidating them by his arms, he had reached the banks of the Rhone, when the consul charged with the conquest of Spain, P. Cornelius Scipio, landing at the eastern mouth of that river, learnt that Hannibal had already entered the Alps. He then leaves his army to his brother Cneius, returns promptly to Pisa, places himself at the head of the troops destined to fight the Boii, crosses the Po with them, hoping by this rapid movement to surprise the Carthaginian general at the moment when, fatigued and weakened, he entered the plains of Italy. The two armies met on the banks of the Tessino (536). Scipio, defeated and wounded, fell back on the colony of Placentia. Rejoined in the neighbourhood of that town by his colleague Tib. Sempronius Longus, he again, on the Trebia, offered battle to the Carthaginians. A brilliant victory placed Hannibal in possession of a great part of Liguria and Cisalpine Gaul, the warlike hordes of which received him with enthusiasm and reinforced his army, reduced, after the passage of the mountains, to less than 30,000 men. Flattered by the reception of the Gauls, the Carthaginian general tried also to gain the Italiots, and, announcing himself as the liberator of oppressed peoples, he took care, after the victory, to set at liberty all the prisoners taken from the allies. He hoped that these liberated captives would become for him useful emissaries. In the spring of 537 he entered Etruria, crossed the marshes of the Val di Chiana, and, drawing the Roman army to the neighbourhood of the Lake Trasimenus, into an unfavourable locality, destroyed it almost totally.