The new commander-in-chief of Libya departed from Carthage immediately after the termination of the mercenary war (perhaps in the spring of 518). He apparently meditated an expedition against the free Libyans in the west. His army, which was especially strong in elephants, marched along the coast; by its side sailed the fleet, led by his faithful associate Hasdrubal. Suddenly tidings came that he had crossed the sea at the Pillars of Hercules and had landed in Spain, where he was waging war with the natives - with people who had done him no harm, and without orders from his government, as the Carthaginian authorities complained. They could not complain at any rate that he neglected the affairs of Africa; when the Numidians once more rebelled, his lieutenant Hasdrubal so effectually routed them that for a long period there was tranquillity on the frontier, and several tribes hitherto independent submitted to pay tribute. What he personally did in Spain, we are no longer able to trace in detail. His achievements compelled Cato the elder, who, a generation after Hamilcar's death, beheld in Spain the still fresh traces of his working, to exclaim, notwithstanding all his hatred of the Carthaginians, that no king was worthy to be named by the side of Hamilcar Barcas. The results still show to us, at least in a general way, what was accomplished by Hamilcar as a soldier and a statesman in the last nine years of his life (518-526) - till in the flower of his age, fighting bravely in the field of battle, he met his death like Scharn-horst just as his plans were beginning to reach maturity - and what during the next eight years (527-534) the heir of his office and of his plans, his son-in-law Hasdrubal, did to prosecute, in the spirit of the master, the work which Hamilcar had begun. Instead of the small entrepot for trade, which, along with the protectorate over Gades, was all that Carthage had hitherto possessed on the Spanish coast, and which she had treated as a dependency of Libya, a Carthaginian kingdom was founded in Spain by the generalship of Hamilcar, and confirmed by the adroit statesmanship of Hasdrubal. The fairest regions of Spain, the southern and eastern coasts, became Phoenician provinces. Towns were founded; above all, "Spanish Carthage" (Cartagena) was established by Hasdrubal on the only good harbour along the south coast, containing the splendid "royal castle" of its founder. Agriculture flourished, and, still more, mining in consequence of the fortunate discovery of the silver-mines of Cartagena, which a century afterwards had a yearly produce of more than 360,000 pounds (36,000,000 sesterces). Most of the communities as far as the Ebro became dependent on Carthage and paid tribute to it. Hasdrubal skilfully by every means, even by intermarriages, attached the chiefs to the interests of Carthage. Thus Carthage acquired in Spain a rich market for its commerce and manufactures; and not only did the revenues of the province sustain the army, but there remained a balance to be remitted to Carthage and reserved for future use. The province formed and at the same time trained the army; regular levies took place in the territory subject to Carthage; the prisoners of war were introduced into the Carthaginian corps. Contingents and mercenaries, as many as were desired, were supplied by the dependent communities. During his long life of warfare the soldier found in the camp a second home, and found a substitute for patriotism in fidelity to his standard and enthusiastic attachment to his great leaders. Constant conflicts with the brave Iberians and Celts created a serviceable infantry, to co-operate with the excellent Numidian cavalry.

So far as Carthage was concerned, the Barcides were allowed to go on. Since the citizens were not asked for regular contributions, but on the contrary some benefit accrued to them and commerce recovered in Spain what it had lost in Sicily and Sardinia, the Spanish war and the Spanish army with its brilliant victories and important successes soon became so popular that it was even possible in particular emergencies, such as after Hamilcar's fall, to effect the despatch of considerable reinforcements of African troops to Spain; and the governing party, whether well or ill affected, had to maintain silence, or at any rate to content themselves with complaining to each other or to their friends in Rome regarding the demagogic officers and the mob.

On the part of Rome too nothing took place calculated seriously to alter the course of Spanish affairs. The first and chief cause of the inactivity of the Romans was undoubtedly their very want of acquaintance with the circumstances of the remote peninsula - which was certainly also Hamilcar's main reason for selecting Spain and not, as might otherwise have been possible, Africa itself for the execution of his plan. The explanations with which the Carthaginian generals met the Roman commissioners sent to Spain to procure information on the spot, and their assurances that all this was done only to provide the means of promptly paying the war-contributions to Rome, could not possibly find belief in the senate. But they probably discerned only the immediate object of Hamilcar's plans, viz. to procure compensation in Spain for the tribute and the traffic of the islands which Carthage had lost; and they deemed an aggressive war on the part of the Carthaginians, and in particular an invasion of Italy from Spain - as is evident both from express statements to that effect and from the whole state of the case - as absolutely impossible. Many, of course, among the peace party in Carthage saw further; but, whatever they might think, they could hardly be much inclined to enlighten their Roman friends as to the impending storm, which the Carthaginian authorities had long been unable to prevent, for that step would accelerate, instead of averting, the crisis; and even if they did so, such denunciations proceeding from partisans would justly be received with great caution at Rome. By degrees, certainly, the inconceivably rapid and mighty extension of the Carthaginian power in Spain could not but excite the observation and awaken the apprehensions of the Romans. In fact, in the course of the later years before the outbreak of war, they did attempt to set bounds to it. About the year 528, mindful of their new-born Hellenism, they concluded an alliance with the two Greek or semi-Greek towns on the east coast of Spain, Zacynthus or Saguntum (Murviedro, not far from Valencia), and Emporiae (Ampurias); and when they acquainted the Carthaginian general Hasdrubal that they had done so, they at the same time warned him not to push his conquests over the Ebro, with which he promised compliance. This was not done by any means to prevent an invasion of Italy by the land-route - no treaty could fetter the general who undertook such an enterprise - but partly to set a limit to the material power of the Spanish Carthaginians which began to be dangerous, partly to secure the free communities between the Ebro and the Pyrenees whom Rome thus took under her protection, a basis of operations in case of its being necessary to land and make war in Spain. In reference to the impending war with Carthage, which the senate did not fail to see was inevitable, they hardly apprehended any greater inconvenience from the events that had occurred in Spain than that they might be compelled to send some legions thither, and that the enemy would be somewhat better provided with money and soldiers than, without Spain, he would have been; they were at any rate firmly resolved, as the plan of the campaign of 536 shows and as indeed could not but be the case, to begin and terminate the next war in Africa, - a course which would at the same time decide the fate of Spain.