Book 9 of Silius Italicus' first-century Latin epic poem Punica begins the narrative of the Battle of Cannae (August 216 BC). This book is an integral part of the epic's three-book movement that narrates one of the largest battles in Roman history. It opens with the dispute between the consuls Paulus and Varro over giving battle, in the face of hostile omens and Hannibal's record of successful combat. On the eve of the battle, the Roman soldier Solymus accidentally kills his father Satricus, thereby presenting an omen of disaster for the Roman army. After Hannibal and Varro encourage their troops, the initial phase of the battle commences. The gods descend to the battlefield, and Mars and Minerva fight the sole full-scale theomachy in Latin epic. Aeolus summons the Vulturnus wind at Juno's request to devastate the Roman ranks. After the gods have departed, Hannibal's elephant troops advance and scatter the Roman forces. The book ends by recapitulating the opening episode: Varro admits his mistake in giving battle and flees the battlefield. This volume is the first full-scale commentary in English devoted exclusively to Punica 9. It features the Latin text with a critical apparatus and a parallel English translation. Detailed commentary notes provide information on literary style, use of language, poetic intertexts, and scholarly interpretation. The Introduction offers further context and background, including sections on Silius Italicus and his era, the historiographic and rhetorical traditions that he adopted, the inter- and intra-textuality of the Cannae episode, and the book's use of diction and metre.