The impious emperor Julian the Apostate did not hesitate to hold communications with the devil. On one occasion, accompanied by a noted magician, he entered a dark, subterranean cavern where the devil was wont to be honored. Horrible noises greeted his affrighted ears. Hideous figures became visible in the gloom, so that the Emperor was terrified.
Mindful of the power of the Sign of the Cross, which he had so often made as a child, he now instinctively signed himself with this holy Sign. Instantly the horrible noises ceased, the dreadful figures disappeared and all was peace. The impious emperor, regaining his lost courage, once more attempted to perform the devilish rites, whereupon the devils again appeared and struck terror into his heart. Again, filled with fear, he made this holy Sign and the devils fled headlong from the cavern. This episode is related both by St. Gregory and St. Augustine.