The narrative interests of the Thebaid greatly depend upon Mars. In Thebaid 3, he seemed all-powerful as he resisted the entreaties of Venus and stirred the Argives to march against Thebes. This journey corresponds to the progress of the narrative towards the warfare that was desired both by Vulcan, for whom Mars has been a virtual agent, and by Jupiter, who also expects his desire for battle to be realized through the war god (Theb. 3.220). But Mars' influence is undone when Bacchus arranges for delay at Nemea, and in fact the war god disappears from the poem. Indeed, as we have seen, in Thebaid 5 Statius uses a simile about birds of war to confine Mars' influence to Thrace. Consequently, the narrative interest in warfare is thwarted. The Argive tarrying at Nemea angers Jupiter, however, and the ruler of the gods thus dispatches Mercury to Thrace to rebuke Mars and to urge him to complete his task of starting the war (Theb. 7.1–2).

This chapter will focus on Mars and the outbreak of war in Thebaid 7. Statius was not the first to address this topic in a seventh book: Ennius' Annales 7 describes the opening of the Gates of War at the start of the Second Punic War, and in Aeneid 7, Aeneas leaves behind the so-called ‘Odyssean’ marvels, travel and adventure in favor of a new world of ‘Iliadic’ battles (Aen. 7.41–2 dicam horrida bella, / dicam acies actosque animis in funera reges).