Between 264 and 241, the Carthaginians had fought the long First Punic War against the Romans, which had culminated with Carthage losing Sicily. After the signing of the peace treaty, the relations between the two powers were friendly until the Romans unexpectedly seized Sardinia. In Carthage, politicians who preferred a less friendly policy towards Rome became more powerful again, and it was decided to conquer Iberia, where a new army could be created.
The general in charge of this project was Hamilcar Barca. At home, he received support from the leader of the democratic politician Hasdrubal, surnamed "The Fair", who was married to Hamilcar's daughter. In 237, the two men went to Gades (Cadíz), and embarked upon the campaign. Later, Hasdrubal returned to Africa. Here, he conducted another campaign, directed at Numidia.
In 229, Hamilcar drowned, and his troops asked the government to make Hasdrubal their leader. The authorities agreed, and in 228, Hasdrubal arrived in Iberia. The new governor secured the Carthaginian position by diplomatic means, such as intermarriage between Carthaginians and Iberians. He himself set the example, and others followed - Hamilcar's son Hannibal Barca also married a native princess. Immediately after this marriage, the Iberian leaders recognized Hasdrubal the Fair as their leader (strategos autokrator, in the words of Diodorus of Sicily).
In 227 (?), Hasdrubal founded a new capital in Iberia, called New Carthage, on a peninsula with two excellent harbors, and not too far from a silver mine. From this base, he proceeded to the north, conquering many towns, including Hemeroscopium, Alonis, and Alicante, which were Greek colonies that belonged to Massilia, an ally of Rome. It comes as not surprise that the Romans sent envoys to strike a compromise with Hasdrubal (226). The river Ebro was to be the northern limit of the Carthaginian conquests; Hasdrubal could keep the three Massilian cities; but he was not to proceed further to the north, where other Massilian colonies were to remain independent.
The treaty had been concluded between the Romans and Hasdrubal, not Carthage. This is remarkable, because other Roman-Carthaginian treaties were concluded between the two states. This suggests that Hasdrubal was considering his position as if he were some sort of king. Several ancient sources even suggest that he wanted to become independent. This is probably incorrect, but his acts may have caused some raised eyebrows in Carthage.
In 221, the man who had done so much to consolidate Carthaginian power in Iberia, was murdered by a Celtic mercenary in the city he had founded, New Carthage. He was succeeded by Hannibal.