Hamilcar was an officer of the army of Hasdrubal Barca, who had in 208/207 BCE arrived in Gallia Cisalpina (the plain of the river Po) to assist his brother Hannibal Barca in his war against the Romans, the Second Punic War (218-202). This war came to an end in 202, when the Roman commander Publius Cornelius Scipio defeated Hannibal at Zama.
However, Hamilcar was not yet defeated. He and his troops were on the plains of the Po, which did not belong to ancient Italy proper and were therefore not part of the peace treaty. Hamilcar continued the war, supported by he Celtic tribes of the Cenomanni and the Insubres. Although he was defeated and killed in 199, the war lasted until 197, when one of the Roman consuls, Gaius Cornelius Cethegus, defeated the rebels in 197.