The epic furnishes a selective account of the major action of the Second Punic War, beginning with Hannibal’s oath of eternal hatred against Rome and ending with Scipio’s triumphant return to the city after his victory at Zama. Between these twin narrative poles, Silius recounts the fall of Saguntum (books 1-2); Hannibal’s march over the Alps with elephants during his journey from Spain to Italy (book 3); the Roman losses at the Ticinus River, the Trebia River, and Lake Trasimene (books 4-6); the stalemate between Hannibal and Fabius (book 7); the Roman disaster at Cannae (books 8-10); Hannibal’s winter at Capua and later failed march on Rome (books 11-12); the falls of Capua and Syracuse (books 13-14); the Roman victory at the Metaurus River (book 15); and Scipio’s successful campaigns in Spain and Africa, culminating in his victory over Hannibal at Zama (books 16-17[18?]). The central theme of the poem is the significance of the Second Punic War in Roman history. In order to organize such a vast undertaking, Silius vigorously engages with his forerunners in the genres of historiography and epic. The two primary literary models for the Punica are the third decade (Books 21-30) of Livy’s history Ab urbe condita, the longest surviving ancient narrative of the Second Punic War, and Vergil's Aeneid. In writing about the Second Punic War, Silius contributes to an extremely rich and diverse array of traditions which have been handed down in Greek and Latin works from all periods of ancient history.
As a whole, the material in the Book VI excursus on Regulus concentrates on a single theme: fides; specifically, the purported dichotomy between fides Romana and fides Punica. Indeed, at several pivotal moments in lines 62-551, either the concept fides or the goddess Fides herself is invoked: by Silius in his capacity as narrator (lines 63-64), by Marus (lines 129-132, 377-380, 490-493, 545-550; cf. lines 386-388), by the Carthaginian Senate (lines 346-349), and by Regulus (lines 467-472, 484-489). In his references to Regulus (all confined to the first six books), Silius consistently hails the Roman consul and general as spes et fiducia gentis / ... Hectoreae and as exemplum fidei.
And yet, in the excursus the poet provides us with a different perspective on Regulus: not his public fides, but his private perfidia toward his wife. Bewildered by his choice to remain in enemy custody, Marcia implores her husband to rejoin his family in his own home, assuring him that she has been faithful to their marriage contract by keeping his bed chaste, preserving his household gods, and providing him with offspring (lines 438-443). Later, when her appeal to Regulus not to desert her but either to remain with her or to take her with him back to Carthage goes unanswered, Marcia condemns him as a perjurer: data foedera nobis / ac promissa fides thalamis ubi, perfide, nunc est? (lines 517-518). In general, this episode, in which Regulus is captured by the Carthaginians in battle, is sent to Rome, and, finally, is taken back to Carthage in order to meet his death by torture, offers an interesting and important case study for the Roman law of postliminium. According to this law, any Roman soldier captured in battle became the slave of his captor and, thereby, lost both his public and private rights as a civis Romanus. If, however, the soldier was able to escape his captor and return to Rome, then he would regain his rights in full, once he had crossed “behind the threshold” (post limen, hence postliminium, i.e., the sacred pomerium of the city). This is the general definition of the ius postliminii, but there are many details about the law and its function which remain unclear. Regulus, however, upon his return to Rome, chose not to exercise his right to postliminium. Instead, he chose to forgo his public rights (i.e., his seat in the Senate) and private rights (access to his wife and family), perhaps because technically he had not escaped his captors but was still in Carthaginian custody. As a consequence, Regulus was not ransomed by the Romans, and, after delivering his message to the Senate, he returned to Carthage for his punishment. In the context of the Punica, these scenes from the excursus transform Regulus’ journey from Carthage to Rome, his rejection of Marcia, and his return from Rome to Carthage into a repetition and reversal of the events of Aeneid I-IV, with Regulus reprising the role of Aeneas and Marcia that of Dido.
In general, Silius, like his fellow Flavian epic poets, Valerius Flaccus and Statius, closely follows the example of Vergil in matters of vocabulary, morphology, and syntax. However, there are a few noteworthy characteristics of Flavian epics which clearly distinguish them from the Aeneid. First and foremost, Silius makes use of the rhetorical figure known as hyperbaton (the rearrangement or transposition of words from their expected word order) more often than Vergil or Ovid. In addition, Silius also uses the infinitive and the participial forms of the verb far more regularly than his predecessors in epic. Accordingly, special note will be taken of these features in the glosses on the two passages from Punica VI.