Causes of the Second Punic War

This essay was originally written in Semester 2 of 2020 for AHIS1020, Rome to the Gracci, at the University of Newcastle. I would like to acknowledge Dr. Hugh Lindsay, who taught the course and provided good feedback on this paper, which I have used to revise it for this website.

Determining the cause of any given war is dependent on the scope with which it is analysed. Singular occurrences may present themselves as part of the chain of events that lead to a war’s beginning, but the influences of those individual occurrences are multi-faceted in nature and must be addressed as such.

At the most immediate level of analysis, the Second Punic War was caused by Rome’s offer of war and Carthage’s acceptance (Poly. 3.33.1-4), and this in turn was caused by the casus belli that Rome derived from Hannibal’s siege of Saguntum and breaking of their treaty with Carthage. As Polybius points out, determining this as the cause rather than simply the beginning of the war is drawing a shallow conclusion (Poly. 3.6.1-3). However it is from this evident point of declaration that the causes, causes of causes, etcetera ad infinitum, can be explored.

Rome’s declaration of war was contingent on Carthage’s acceptance of Hannibal’s taking of Saguntum, where Carthage could have disavowed Hannibal and maintained peace (Poly. 3.20.8). However, to even engage with this prospect, Carthage would have had to accept the terms of the offence and the interpretation presented by the Roman embassy of the treaty they held together. According to Polybius, the Carthaginian senate threw out the offence as a misinterpretation of the treaty (Poly. 3.21.5), as well as arguing over which treaty was in place at that time (Poly. 3.21.1-3).

The matter of the Carthaginian senate’s consideration of the treaty agreed to by Hasdrubal is only of note, beyond having created friction with the Roman embassy in their deliberation (Poly. 3.29.2), if Saguntum had become an ally of Rome by the time of Hasdrubal’s agreement to that treaty. Even so, the temporally fixed nature of the allies referred to by the treaty, as asserted by the Carthaginian senate, was rejected by the Roman embassy (Poly. 3.29.6) and this was thoroughly justified by Polybius (3.29.7-10).

It would be easy to side with the Roman perspective here, as the Carthaginian assertions that Polybius characterises appear rather ridiculous. Though, without knowing how the treaties were actually laid out, it is impossible to be certain what interpretations would be reasonable to draw from the wording of those treaties. Polybius even admits that “the ancient Roman language differs so much from the modern that it can only be partially made out, and that after much application, by the most intelligent men” (Poly. 3.22.3).

It is here that a stark contradiction is found in Polybius’s account. He states the Roman embassy responded to Carthage’s justification in the way described above, but then also states that Rome made “no other reply” but the ultimatum given by the oldest member of the embassy (Poly. 3.33.1-4). It is possible that Carthage doubled down on their case without deviation after the Roman reply, eliciting the ultimatum, but this is not explained in Polybius’s account.

Livy gives some details that significantly shifts the perspective of these events. If Hannibal sent word to Carthage upon the Roman embassy’s presence in Iberia in order to undermine the efforts of that embassy (Livy, 21.9.3-4), then the seemingly illogical arguments presented by the Carthaginian senate could be interpreted as a kind of filibuster. Additionally, Livy presents Saguntum as explicitly protected by the treaty with Hamilcar (Livy, 21.2.7, 21.10.5) and that the justification given by the Carthaginian senate is rather that Saguntum started the conflict and so Hannibal had not offended against their treaty (Livy, 21.11.2).

This conflict between the two sources demands reflection on their comparable veracity. Polybius wrote in the 2nd century BC, whereas Livy wrote in the late 1st century BC. Considering the Second Punic War takes place in the last two decades of the 3rd century BC, Polybius would have been writing whilst the events were still in living memory, whereas Livy’s writing wouldn’t have taken place until all of those who had experienced or were directly affected by the war would have been long dead.

The consideration of this is twofold. In the first case Polybius, being surrounded by the events following the war, would have access to primary witnesses; whereas Livy would only have inherited knowledge through passed-down stories and written sources such as Polybius. One might consider then that Polybius would give the more pure account of events, but it is possible that Livy had access to other perspectives that were collated and perhaps published over time that Polybius didn’t have access to. In the second case Polybius would have been immersed in the zeitgeist and thus the biases of the time, whereas Livy could be considered more removed from the sociopolitical environment of the time and thus more objective in his writing. However, this too must be balanced by consideration that Polybius was Greek and so geographically separated from the Punic Wars, whereas Livy was Roman and not safe from the biases of his own time and place.

It stands to reason that if the protection of Saguntum, by the treaty between Rome and Carthage, was not under contention, and that Carthage had instead claimed that Saguntum started the conflict, then Polybius would have mentioned as such and not placed such great emphasis on the matters he presented of the meeting between the Roman embassy and the Carthaginian senate, but the whole matter cannot be determined with any certainty due to the contradiction in Polybius’s narrative as mentioned above.

Regardless of these discrepancies, the decision to go to war was immediately due to Carthage’s refusal to acknowledge the offence for which the embassy had travelled, and in turn due to Rome’s responsibility to respond to the attack on their ally, Saguntum. The nature and degree of that responsibility would depend on the nature of Rome’s relationship with the Saguntines, and the events leading up to the attack on Saguntum.

At a broader level of analysis, the attitudes and patterns of behaviour leading up to the second Punic War’s catalysing incidents play necessary roles: Rome’s system of allyship through the Mediterranean and the pressures that placed on Rome’s reaction to external conflicts, the Barcid reaction to the levy imposed on Carthage and how that gave them cause to expand through Iberia, as well as Hannibal’s attitude towards Rome. Unfortunately, such further analysis is beyond the scope of this essay.


Polybius. (2010) The Histories, Volume II: Books 3-4. Translated by W. R. Paton. Revised by F. W. Walbank, Christian Habicht. Originally Loeb Classical Library, published on Chicago University Website. Retrieved from*.html. Accessed 2020 Oct 1

Livy, T. (1912). The History of Rome. Translated by Rev. Canon Roberts, Ed. Published on Tufts University Website. Retrieved from Accessed 2020 Oct 1

Feature Image by Torkos Akos on Unsplash

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