"The Vision of the Cross" is located in the "Sala di Costantino" ("Hall of Constantine"). In the painting, emperor Constantine I is seen just before the Battle of the Milvian Bridge on October 28, 312. According to legend, a cross appeared to Constantine in the sky, after which as seen in the fresco and following Eusebius of Caesarea "Vita Constantini", he adopted the Greek motto "Εν τούτῳ νίκα", i.e. "By this, conquer", a motto that has been rendered in Latin as "In hoc signo vinces", i.e. "In this sign you shall conquer".