But side by side with the government a military party had come into being, and its leader, Hamilcar Barca, who had held his ground unconquered to the last moment in Sicily and who afterwards (in concert with Hanno the Great, the general of the aristocratic party) quelled the mutiny of the mercenaries, was burning with eagerness to take vengeance on Carthage’s autocratic and perfidious adversary. The power was in his hands and he was determined to use it to make every preparation for a fresh and decisive campaign. At the end of the year 237, immediately after the suppression of the mutiny, he proceeded on his own responsibility to Spain, and there conquered a new province for Carthage, larger than the possessions she had lost to Rome. By allying himself with the popular party in Carthage, and giving his daughter in marriage to Hasdrubal, their leader, Barca gained a strong following in the capital; and even the dominant aristocracy, in spite of the suspicion with which they regarded the self-willed general--and not without good reason--could not but welcome gladly the revenues of the new province out of which they could defray the war indemnity to Rome. Hamilcar fell in 229; Hasdrubal, who took over his command, postponed the war against Rome and entered into an agreement with the latter, who was suspiciously watching developments in Spain, by which he pledged himself not to cross the Ebro. This made it possible for Rome to bring the Celtic War to an end and conquer the valley of the Po while Hasdrubal was organising the government of Spain. But when, after the assassination of Hasdrubal in 221, his youthful brother-in-law, Hannibal, then twenty-four years of age, took over the command, he promptly revived his father’s projects. In the year 219, by picking a quarrel with Saguntum, which had put itself under the protection of Rome, and attacking the city, which he took at the beginning of 218, he brought about a conflict which forced both Rome and the reluctant government of Carthage into hostilities. The declaration of war was brought to Carthage by a Roman embassy in the spring of 218. While Rome was making preparations for an attack on Spain and Africa simultaneously, Hannibal advanced by forced marches upon Italy by land, succeeded in evading the Roman army under Publius Scipio which had been landed at Massilia, and reached Italian soil before the beginning of winter. Rome was thereby foiled in her intention of taking the offensive. At the end of 218 and the beginning of 217 he had annihilated by a series of tremendous blows the Roman armies opposed to him, and, reinforced by hordes of Celts from the valley of the Po, had opened a way for himself into the heart of Italy.