During the winter Hannibal made every preparation to ensure the tranquillity of Spain while he was absent.

In order to lessen the number of possible enemies there he raised a body of twelve hundred horse and fourteen thousand infantry from among the most turbulent tribes, and sent them across to Africa to serve as garrisons in Carthage and other points, while an equal number of African troops were brought over to garrison Spain, of which Hasdrubal, Hannibal's brother, was to have the government during his absence.
Hanno, an able general, was to command the force which was to be left in southern Gaul to keep open the communications between the Pyrenees and the Alps, while the youngest brother, Mago, a youth of about the same age as Malchus, was to accompany him to Italy.

Hannibal's wife and a child which had been born in the preceding spring, were sent by ship to Carthage.
In the early spring the march commenced, the army following the coast line until it reached the mouth of the Ebro.

The mountainous and broken country lying between this river and the Pyrenees, and now known as Catalonia, was inhabited by fierce tribes unconquered as yet by Roman or Carthaginian.

Its conquest presented enormous difficulties.