Of the many accounts of the Battle of the Milvian Bridge in a.d. 312 written soon after the conflict, only those of Eusebius of Caesarea have Maxentius cross the Tiber on a bridge of boats to face the forces of Constantine. This detail, it is here argued, suggests that Maxentius may be seen as a latter-day Xerxes, the Persian emperor who, in preparation for his invasion of Greece in 480 b.c., famously spanned the Hellespont with a pair of boat-bridges. The article first reviews the seminal accounts of Xerxes’ feat in Aeschylus’ Persians and Herodotus’ Histories, and next discusses the story's long afterlife in subsequent Greek (and Latin) authors, including those of Late Antiquity. Close analysis of Eusebius’ battle narratives in his Ecclesiastical History (9.9.3–8) and in his Life of Constantine (1.38) reveals that their vocabulary echoes the distinctive language used by Aeschylus, Herodotus and later writers in reference to Xerxes’ achievement. The article concludes by exploring the implications of this identification of Maxentius with Xerxes. It exemplifies two venerable tactics in Roman political propaganda: that of portraying a native rival as a foreign enemy and that of mapping the Persian Wars onto contemporary events. As Xerxes rediuiuus, Maxentius is cast as the quintessential barbarian tyrant, an Eastern despot resident in Rome.