Following its defeat in the First Punic War, the Carthaginian Empire looked to rebuild its power base by controlling Spain. Hamilcar Barca, the premier Phoenician general, humiliated and angered over Rome's peace terms, and the seizure of Sardinia during Carthage's own mercenary war, looked to Spain as an overland launching point for future action against Rome. Before long, Hamilcar would pass his hatred and obsession with Rome onto his son Hannibal, who would prove to be one of the greatest generals in history. By 220 BC, while the Romans were occupied in Cisalpine Gaul and Illyricum, Hannibal, and his brother Hasdrubal established control of the Hispania peninsula as far north as the Ebro (Iberus) River.
Earlier, while Hamilcar was still establishing control of Spain, Rome was concerned over Carthaginian resurgence. In the 220's BC, they established a treaty with Carthage limiting expansion to anything south of the Ebro. Saguntum, a small town in that territory, had entered into an alliance with Rome, giving the Romans a small stronghold in the heart of Carthaginian lands.
Hannibal rose to power in 221 BC after the assassination of his father, Hamilcar. Instilled from birth with his father's hatred of Rome and raised to be a leader of men, Hannibal became the greatest threat to Rome in its history. With his assumption of command, he immediately set out to subdue rebellious tribes in his rear with his eventual goal to invade Italy. Over the next year, Hannibal would be satisfied with the situation in Spain and looked to Saguntum to goad the Romans into war and justify his planned invasion. By 220 BC, Hannibal laid siege and opened the door to one of the ancient world's great wars.
After an eight month siege, Saguntum was captured. Having collected the spoils, Hannibal wintered in Carthago Nova while planning for his over Alps invasion of Italy in the Spring. Since Rome's victory in the first Punic War, the vaunted Carthaginian fleet was no match for Rome, and Hannibal knew that the Romans would only be vulnerable from an overland attack. He hoped that by marching through southern Gaul and northern Italy, recent conflicts between the Romans and local tribes would boost his ranks with fresh angry recruits.
Roman diplomatic attempts over the winter to seek justice from Carthage over Hannibal's siege met with failure. In negotiations with the Carthaginian capital the Roman envoy Fabius made a last ditch effort to avert war. According to Livy, pulling the folds of his toga into his hands Fabius said, "we bring you peace and war. Take which you will.' Scarcely had he spoken when the answer no less proudly rang out: 'Whichever you please, we do not care.' Fabius let the gathered folds fall, and cried: 'We give you war.'