Veii, an Etruscan city a short march from Rome, held out against Roman siege for a full decade before falling around 396 BCE under Camillus's command, a length of resistance Roman tradition treated as extraordinary and explained in religious as much as military terms. Ancient accounts describe Camillus, before the city's final capture, performing evocatio, formally calling upon Veii's own tutelary goddess, Juno Regina, to abandon her people and accept a new and better home at Rome, addressing her by every name and title that might apply on the premise that a deity's protection could genuinely be persuaded away from a city it no longer wished to defend. Whether the rite preceded the city's fall or interpreted it afterward, ancient sources present the two as connected: Veii's capture and Juno's departure from it as a single religious and military event, with the goddess's cooperation treated as a necessary condition of Roman success rather than a mere afterthought. Following the victory, Camillus is credited with formally establishing Juno Regina's cult in a new temple on Rome's Aventine Hill, physically enacting the relocation the evocatio had proposed and giving Rome a visible token that the ritual had worked.
Modern historians of Roman religion treat the episode as the best documented ancient instance of evocatio precisely because it comes with this before and after structure, a named performer, a named deity, and a physical temple marking the transfer, rather than the more fragmentary references that survive for the rite's few other attested uses, including the later destruction of Carthage.