 "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.