The Celtic tribes of the neighborhood were won over to his side.

Troops collected from these were stationed along the river, but Scipio's main army remained at Massilia.
It was Hannibal's policy to cross the river before Scipio arrived with his troops.

He obtained all the boats possible, and constructed numerous rafts to transport his main body of troops.

A detachment of soldiers was sent up the river with orders to cross at the first available place, and, returning on the opposite bank, to surprise the Celtic forces in the rear.

The plan succeeded.