Evoking the Pagan Past: Instinctu divinitatis and Constantine’s Capture of Rome

The inscription on Constantine’s arch claims that he defeated Maxentius “by the instigation of the divine”(“instinctu divinitatis”). Scholars long have recognized the significance of this phrase in the context of Constantine’s vision or visions before the Battle of the Milvian Bridge. This study examines the phrase from a philological perspective and demonstrates that it likely was formulated by pagan senators rather than the emperor himself. It argues that these senators probably were the very aristocrats who had supported Maxentius and that they used the iconography of the arch and its inscription to point Constantine toward a pagan interpretation of his success in battle. By tracing the phrase to a passage in Livy, it further demonstrates that the interpretation of the battle on the arch is heavily colored by the Republican war ritual of evocatio, whereby a city’s protective deity is called forth in anticipation of an assault. Without contending that an evocatio was actually performed, it shows how the arch’s inscription and the Latin panegyrics that treat the battle deploy the language and concepts of evocatio in order to explain how Constantine succeeded in overcoming a foe who had relied on the protection of the Urbs Roma.