Evocatio

Evocatio is a term from ancient Roman religion used to apply to the procedure for drawing a foreign tutelary god to Rome. In his Saturnalia, Macrobius comments on an evocatio in Vergil. Macrobius calls it a vetustissima Romanorum mos (most ancient custom of the Romans), designed to lure the foreign god, from his post defending the foreign city, by the promise of games and temples.

The most famous evocatio occurred in 392 B.C. when the Roman dictator Camillus, in an effort to defeat the Veiians, summoned the tutelary deity of the Etruscan town of Veii to the city of Rome, and built her a temple on the Aventine. The statue of the goddess became the Roman's goddess Juno Regina.

References:

• _{"Two Types of Roman devotio," by H. S. Versnel; Mnemosyne Fourth Series, Vol. 29, Fasc. 4 (1976), pp. 365-410.}
• _{"Foreign Cults in Republican Rome: Rethinking the Pomeria Rule," by Eric M. Orlin; Memoirs of the American Academy in Rome, Vol. 47 (2002), pp. 1-18}
• _{"Scipio, Laelius, Furius and the Ancestral Religion," by Elizabeth Rawson; The Journal of Roman Studies, Vol. 63 (1973), pp. 161-174}