Siege of Saguntum The Siege of Saguntum was a battle which took place in 219 BC between the Carthaginians and the Sagunt ines . The battle is mainly remembered today because it triggered one of the most important wars of antiquity , the Second Punic War . Hannibal ' s plans . After Hannibal was made supreme commander of Iberia ( 221 BC ) at the age of 26 , he spent two years maturing his plans and completing his preparations to secure power in the Mediterranean . The Romans did nothing though they received ample warning of Hannibal ' s preparations . They were yet to learn of the talent and determination of the man with whom they had to deal . The Romans thought that they could strike down this Carthaginian youth whenever they pleased , and no special effort would be required . The Romans even went so far as ignoring Hannibal by turning their attentions to the Illyrians who had begun to revolt . Because of this , the Romans could not react when news reached them that Hannibal was besieging Saguntum in south - east Iberia . They were disgruntled that Hannibal had broken the treaty set after the First Punic War . Here Hannibal showed a side that is not all too different from that of the Roman Republic , as Rome had recently annexed Sardinia despite a treaty which had explicitly forbidden them from doing so . The capture of Saguntum was essential to Hannibal in his overall plan . The city was one of the most fortified in the area and it would be a poor move to leave such a city in the hands of his enemy . Hannibal also looked for plunder to keep his army happy ( mostly mercenaries from North Africa , Iberian Peninsula and Gaul ) . The money from the city could also be spent on keeping any political opponents down back in Carthage . The siege . During Hannibal ' s assault on Saguntum he suffered some losses due to the extensive fortifications and the tenacity of the defending Saguntines , but his troops stormed and destroyed the city ' s defenses one at a time . The Saguntines turned to Rome for aid , but none was sent . In 218 BC after enduring eight months of siege the Saguntines ' last defences were finally overrun . Hannibal offered to spare the population on condition that they were " willing to depart from Saguntum , unarmed , each with two garments " . When they declined the offer and began to sabotage the town ' s wealth and possessions , every adult was put to death . This marked the beginning of the Second Punic War . Hannibal now had a base from which he could supply his forces with food and extra troops . Aftermath . After the siege , Hannibal attempted to gain the support of the Carthaginian Senate . The Senate ( controlled by a relatively pro - Roman faction led by Hanno the Great ) often did not agree with Hannibal ' s aggressive means of warfare , and never gave complete and unconditional support to him , even when he was on the verge of absolute victory only five miles from Rome . In this episode however , Hannibal was able to gain limited support which permitted him to move to Carthago Nova where he gathered his men and informed them of his ambitious intentions . Hannibal briefly undertook a religious pilgrimage before beginning his march toward the Pyrenees , the Alps , and Rome itself . The next phase of the war was marked by extraordinary Carthaginian victories at Trebia , Lake Trasimene and , perhaps most notably , at the Battle of Cannae .