What were the causes of the Second Punic War

A re-imagining of Hannibal and his army in battle in Spain

Hannibal Barca (247-183 BCE) is one of the best-known figures from the Ancient World. He is generally considered one of the greatest generals in history and Rome’s most formidable enemy. Hannibal in the Second Punic War (218-201 BCE) almost inflicted a total defeat on the Roman Republic. This war is often simply known as Hannibal’s war. The story of the conflict is well known, such an event as his heroic crossing of the Alps has become legendary. Less well known, are the causes of the Second Punic War. Below is a discussion of the origins of the second great war between Carthage and Rome. It will be argued that the causes of the Second Punic War were Carthage’s intrigues with the Celts, Hannibal’s rivalry with Rome in Spain, and the great Carthaginian’s general thirst for revenge on Rome.


Carthage had been found in the 8th century BC by Phoenicians on the coast of North Africa. They were great traders and farmers, and soon they had created a great city, and they dominated large tracts of the coast of Northern Africa. From here, they established a trade network across the Mediterranean. The Carthaginians had a large navy and were the dominant maritime power in the western Mediterranean. They first established colonies and later developed a maritime Empire. They contested the control of Sicily with the Greeks.

The rise of Rome in the Third Century led to their interference in Sicily. They were initially invited into Sicily by the Greeks, who were fearful of the Carthaginians. This invitation led to tensions with the Carthaginians and ultimately led to the outbreak of the First Punic War.[1] This was a brutal war, and both sides inflicted severe defeats on each other.

After many years’ of fighting, there was a stalemate, Rome knew that it could only defeat the Carthaginians by ending their supremacy at sea. Rome eventually built a fleet, and after initial defeats, they conquered and smashed the Punic navy and won a total victory. They imposed very harsh terms on Carthage as part of the peace treaty. The Romans demanded that the Carthaginians evacuate Sicily.

After the treaty was signed, the Romans illegally seized the Punic possessions of Sardinia and Corsica. It also placed restrictions on the size of the Punic navy and demanded reparations. Their defeat in the First Punic War saw Carthage stripped of most of its empire, apart from its North Africa territories and an enclave in Spain.[2]

The Barcids in Spain

Hannibal was a member of the powerful Barca clan, one of the most influential in Carthage. His father Hamilcar, had valiantly fought the Romans in Sicily and was widely regarded as a great commander. He wanted to restore the Carthaginian Empire and to make it strong again so that it could defend itself against Roman aggression. Hamilcar decided to expand the territory of Carthage in Spain. The North Africans had a small foothold in Spain and Hamilcar organized an expedition to the area. He was accompanied by his Hannibal who was only nine years old. Hamilcar was a brilliant leader and strategist and he soon began to conquer extensive territories in Spain. He cleverly entered into alliances with some of the local tribes and exploited the internal divisions of others.

Hamilcar’s army was composed mainly of mercenaries, from Spain and North Africa, who were personally loyal to him. This allowed him to create a great Carthaginian Empire in the south and center of Spain, he also controlled much of Portugal. This was viewed with alarm in Rome and they were troubled by the revival of the Carthaginians power. Hamilcar drowned while crossing a river during a battle and his command was given to his son-in-law the Fair. He continued the strategy of Hamilcar and continued to expand the Punic presence in Iberia [3]. In 221 BCE Hasdrubal was assassinated by a local tribesman, many believe at the instigation of the Romans. This is even though he had signed a treaty with Rome that allowed the Carthaginians influence south of the Ebro River and Rome assigned a ‘sphere of influence’ north of that river. The army acclaimed Hannibal and he became its commander at the age of 26. Hannibal sought to consolidate the power of the Carthaginians in Iberia and he stormed several important fortresses. He faced a coalition of rebellious Spanish tribes but Hannibal defeated them at the Battle of the River Tagus.[4]

Celtic and Carthaginian Alliance

As part of the peace treaty that ended the First Punic War, Carthage could not intervene in the affairs of Italy. However, there was a faction in Carthage that was determined to renew the war with Spain. They were supported by the Barcids in Spain. It seemed that the Barca’s first Hamilcar, then Hasdrubal and finally Hannibal supported a faction in Carthage that wanted a war of ‘national revenge’. This faction briefly won a majority in the Carthaginian Senate or Assembly and entered into a secret agreement with the Celts in Northern Italy.[5] They were based in the Po Valley and had a formidable army and they had once even sacked Rome. The Romans feared the Celts ever since.

The Celts with the support of the Carthaginians planned to move south into Roman territory. However, the Romans became aware of the plan and they launched a preemptive strike. Rome was now very much afraid of a Celtic-Carthaginian alliance and attacked Cisalpine Gaul (Southern France) to deny the Carthaginians an opportunity to attack the Republic. Rome had been complacent about the Carthaginians and they adopted a more aggressive stance. The adopted a strategy to contain Hannibal in Spain. The Hannibal inspired attempts by the Carthaginians to engineer a Celtic or a Celtic-Carthaginian invasion placed Rome on a war-footing.[6]

Crisis in Spain

A relief showing a battle between Punic and Roman armies

The Romans had begun to focus more on Spain but after the assassination of Hasdrubal, they became distracted by events elsewhere. They became embroiled in a war in Illyria [7]. This allowed Hannibal to consolidate his position in Spain. The capture of Saguntum was essential to Hannibal's plan. This was originally a Greek city but later was composed of a mixed population of Greeks, Romans, and Iberians. The city was a very prosperous trade center and it was strongly fortified. Hannibal regarded Saguntum as key to his position in Spain. Furthermore, the wealth of the city tempted him as he needed to pay his men who were all mercenaries. Hannibal laid siege to the city. The citizens of Saguntum resisted bravely and they defied Hannibal and his army for long eight months.[8] Rome was an ally of the city and they had guaranteed the safety and the security of the city. During Hannibal's assault on Saguntum he suffered heavy losses as he attempted to storm the city’s fortifications and because of the ferocity of the defending Saguntines [9]. After many attacks, his troops stormed and destroyed the city's defenses by attacking them one at a time. Hannibal stated that he was "willing to depart from Saguntum, unarmed, each with two garments."[10]

When the inhabitants rejected the offer Hannibal had every adult put to death and enslaved the children. Rome was technically an ally of Saguntum, but the Republic was not able to help it. Many saw the siege and the destruction of the city as an unofficial declaration of war. The Romans now reasoned that Hannibal did not want to respect past agreements and the allies of Rome.[11] The Romans had allowed Hannibal to become too strong in Spain and now he was able to use it as a base. Hannibal used the manpower and resources of Spain to recruit a massive army, some 90,0000 strong, according to modern historian’s estimates.[12] Hannibal also obtained war-elephants. After he set out from Spain he crossed the Alps and advanced into Italy where he soon won a series of remarkable victories at the battles of Trebia, Lake Trasimene, and the Battle of Cannae.

Carthage and Hannibal

The Second Punic War was often known as Hannibal’s War in Rome.[13] It was in a real sense the personal war of Hannibal. The Barcid was the main driver of the conflict between Carthage and Rome. The government of Carthage was divided over their support for Hannibal in Spain and they were not really in favor of another war with Rome. Their city had suffered too much in the war and in its aftermath during the ‘Mercenary War’ and there was a strong pro-peace party in the city.[14]

Most of the leadership in Carthage was opposed to another war with Rome and tried to block Hannibal’s strategy. The Senate or Assembly was controlled by a party that wanted peaceful co-existence with Rome and distrusted Hannibal. However, despite the elite Carthaginians' opposition to the war, under the leadership of Hanno the Great, they were unable to restrain Hannibal.[15]

While Hannibal was technically loyal to Carthage, he often acted as an independent sovereign in Iberia. The Carthaginians did not control him in Iberia. Indeed, the Barcid led the city-state into a war that they did not want. Hannibal could use his massive wealth from his Iberian conquests to bribe many Carthaginians politicians to support his anti-Roman policies.[16] They were populists who could sway public opinion and put pressure on the pro-peace faction to support Hannibal.

Hannibal was powerful enough that he could effectively hijack the Carthaginian Senate and to dictate its foreign policy. He was even able to drag it into another war with Rome despite opposition from Carthaginian citizens. One of the key reasons for the outbreak of the Second Punic War was the inability of Carthage to restrain Hannibal, who had become too powerful. If the Carthaginian Senate had been able to control the Barcid, a war between Hannibal and Rome could have been averted.[17]

The character of Hannibal

A 19th-century painting of Hannibal and his war elephants crossing the Alps

It is not fashionable these days to assign much importance to the role of individuals in history. Hannibal was determined to avenge the death and defeat of his people in the First Punic War. He was determined like his family to defeat Rome and it became an obsession. From his earliest childhood, he was raised by his father to hate Rome and to seek his destruction.[18] This was not typical of all or many in the Carthaginian elite. A story is told of how Hannibal became the life-long enemy of Rome. Once in Spain is father brought him to an altar. There Hamilcar ‘commanded the young Hannibal to lay his hand on the body of the sacrificial victim and to swear that he would never be a friend to Rome."[19] Hannibal was bound by this oath and he never wavered from it and he became the Republic’s greatest enemy. The personality of Hannibal, his genius, and his hatred of the Romans was crucial in the outbreak of the war. However, even without Hannibal, many historians argue that another war between the two greatest powers in the Western Mediterranean was inevitable.[20]


The war between Hannibal and Rome was one of the most decisive in history. It was a ferocious struggle and it could have led to the destruction of Rome and this could have changed the course of World History. The origins of the Second Punic War, which was very much Hannibal’s war, were the following. The rising power of the Barcid family in Spain upset the balance of power between Carthage and Rome and this destabilized the peace that was agreed upon at the end of the First Punic War. Another was the Carthaginian faction who opposed the peace with Rome's attempts to create an alliance with the Celts in the North of Italy. The inability of the Carthaginian Senate to impose their will on Hannibal was also critical. If one was to select the most crucial factor that led to the war it was the burning hatred of the great Carthaginian for Rome.


  1. Garland, Robert. Hannibal (London: Bristol Classical Press, 2010), p. 45
  2. Garland, p. 47
  3. Hoyos, Dexter. Hannibal's dynasty power and politics in the western Mediterranean, 247-183 BC. (London: Routledge, 2003), p 45
  4. Hoyos, p. 113
  5. Livy, History of Rome, xxi
  6. Livy, History of Rome, xxiii
  7. Livy, History of Rome, xiv
  8. Hoyos, p. 117
  9. Garland, p. 116
  10. Polybius, The Rise of Rome, iii
  11. Livy, History of Rome, xxiv
  12. Garland, p. 117
  13. Garland, p. 113
  14. Rich, John. "The origin of the second Punic War." Bulletin of the Institute of Classical Studies. Supplement, no. 67 (1996), p 37
  15. Polybius, Rise of Rome. Iii
  16. Garland, p 116
  17. Garland, p. 121
  18. Bickerman, Elias J. (1952). "Hannibal's Covenant". American Journal of Philology. 73 (1): 1–23
  19. Polybius, 3.11
  20. Bickerman, p 22