Both Carthage and Rome were in the process of mobilizing their resources for the coming war.
Hannibal commanded the Carthaginian forces, while the Roman Senate decided on the Roman deployment of forces.

The Roman navy had already been mobilized by 218 BC, having launched 220 quinqueremes, perhaps in preparation for the Second Illyrian War (220/219 BC).
Consul Tiberius Sempronius Longus had received two legions, 8,000 infantry and 600 cavalry, plus 16,000 allied infantry and 1,800 allied cavalry and instructions to sail for Sicily in 160 great warships and 12 light galleys and from there to Africa (he never made it) provided the other consul, Publius Cornelius Scipio, could keep Hannibal out of Italy.
Scipio received two legions of the same number of infantry and cavalry plus 14,000 allied infantry and 1,600 allied cavalry with 65 banked ships for transport.
Lucius Manlius was given two legions with 10,000 allied infantry and 1,000 cavalry.
Gauls of the Boii and Insubres tribes in northern Italy had attacked the settlers intended to build the Roman colonies of Placentia and Cremona, and had penned them and a small Roman relief force in Mutina.
One of the two legions and an allied detachment originally intended for Scipio was diverted for the relief of Mutina under the Praetor Lucius Manlius Vulso.
This happened as Scipio retreated to Placentia after the Battle of Ticinus and to Cremona after the Battle of the Trebbia.
A fresh legion, together with a contingent of allied troops, was raised to replace this detachment, delaying Scipio's departure.
Both Carthage and Rome were in the process of mobilizing their resources for the coming war. Hannibal commanded the Carthaginian forces, while the Roman Senate decided on the Roman deployment of forces.
The Roman navy had already been mobilized by 218 BC, having launched 220 quinqueremes, perhaps in preparation for the Second Illyrian War (220/219 BC). Consul Tiberius Sempronius Longus had received two legions, 8,000 infantry and 600 cavalry, plus 16,000 allied infantry and 1,800 allied cavalry and instructions to sail for Sicily in 160 great warships and 12 light galleys and from there to Africa (he never made it) provided the other consul, Publius Cornelius Scipio, could keep Hannibal out of Italy. Scipio received two legions of the same number of infantry and cavalry plus 14,000 allied infantry and 1,600 allied cavalry with 65 banked ships for transport. Lucius Manlius was given two legions with 10,000 allied infantry and 1,000 cavalry. Gauls of the Boii and Insubres tribes in northern Italy had attacked the settlers intended to build the Roman colonies of Placentia and Cremona, and had penned them and a small Roman relief force in Mutina. One of the two legions and an allied detachment originally intended for Scipio was diverted for the relief of Mutina under the Praetor Lucius Manlius Vulso. This happened as Scipio retreated to Placentia after the Battle of Ticinus and to Cremona after the Battle of the Trebbia. A fresh legion, together with a contingent of allied troops, was raised to replace this detachment, delaying Scipio's departure.
Battle of Rhone Crossing