Hannibal, brought up in the company of the soldiers, became the best horseman and the best archer of the army. War was his only aim in life; his only needs, therefore, were a horse and arms. He had made himself so popular that at the death of Hasdrubal who was in the command of the army, the soldiers elected him general without waiting for orders from the Carthaginian senate. Thus Hannibal found himself at the age of twenty-one at the head of an army which was obedient only to himself. He began war, regardless of the senate at Carthage, by advancing to the siege of Saguntum, a Greek colony allied with Rome; he took this and destroyed it. The glory of Hannibal was that he did not wait for the Romans, but had the audacity to march into Italy to attack them. As he had no fleet, he resolved to advance by land, through the Pyrenees, crossing the Rhone and the Alps. He made sure of the alliance of the Gallic peoples and penetrated the Pyrenees with an army of 60,000 men, African and Spanish mercenaries, and with 37 war-elephants. A Gallic people wished to stop him at the Rhone, but he sent a detachment to pass the river some leagues farther up the stream and to attack the Gauls in the rear; the mass of the army crossed the river in boats, the elephants on great rafts. He next ascended the valley of the Isère and arrived at the Alps at the end of October; he crossed them regardless of the snow and the attacks of the mountaineers; many men and horses rolled down the precipices. But nine days were consumed in attaining the summits of the Alps. The descent was very difficult; the pass by which he had to go was covered with ice and he was compelled to cut a road out of the rock. When he arrived in the plain, the army was reduced to half its former number.