Please note that many stretches of the
boundaries in the Constantine map are
only approximate. The provincial boundaries
within Britain are unknown.
According to the Life of Constantine by Eusebius, in 312 A.D. the soon-to-be Emperor was in Gaul to do battle. The Emperor, before his battle at the Milvian Bridge, is reported to have seen a miraculous flaming cross in the middle of the day with a legend that read (when translated) 'By this Conquer.' This event is believed to have led to the emperor's conversion to Christianity and his adoption of what he saw in the vision as his symbol of his reign.
"Historians have recorded there were two parts to Constantine’s experience with the so-called sun cross. One was a vision in the sky that both he and his army supposedly saw while at a pagan temple of Apollo in Gaul (France), 310 AD. Then later, in 312 AD, he reportedly had a dream, just before his triumphant battle at the Milvian Bridge. In the dream, he again saw a vision of a sun cross.
". . . Constantine and his army were said to have witnessed a sun halo in the spring, which is a natural phenomenon that most often occurs in that season of the year. This was a double-ring halo, with rings of three pseudo suns arranged in cross-formation around the sun. Apparently this visual of 310 AD had a light-cross in the center. Then, about two years later, the dream reportedly occurred just before Constantine faced Maxentius, in the fall of 312 AD. (He) initially took the vision to be from his pagan god, Sol, but reconsidered after consultation with Christians in his entourage, concluding that both signs came from God" (Music of the Appointed Times by Dwight Blevins, pages 22 - 23)
Through his Edict of Milan in 313 A.D., the Emperor halted 246 years of state sponsored persecution against those who believed in Jesus Christ as the Messiah. He also subsequently stopped the bloody practice of slaves, criminals and even citizens of Rome doing battle with each other as entertainment for the masses. Nero, during one of his spectacles, showed no less than 400 Roman Senators and 600 knights battling each other as quickly trained gladiators.
The first Roman effort against Christians took place under Emperor Nero. According to Foxe's Book of Martyrs, the path of trying to stamp out Christianity began when Nero ordered the city of Rome be set on fire. After the fire reached its ninth day the Emperor was beginning to be blamed for the destruction. Seeking to deflect criticism away from himself, Nero began to accuse Christians of starting the fires. Persecution soon set in and many believers were killed in the Roman arena called the Circus Maximus.
A total of ten Roman-backed persecutions took place before the reign of Constantine. The first one occurred during Emperor Nero's reign in 67 A.D. The second took place under Domitian in 81 A.D. The next were under Trajan in 108, Marcus Aurelius Antoninus in 162, Severus in 192, Maximus in 235, Decius in 249, Emperor Valerian in 257 and Aurelian in 274. The tenth of ten state-sponsored persecution took place under the reign of Diocletian in 303 A.D.
Christianity was made the official state religion in 380 A.D. The impact of the edict had a profound impact on Christian history as Foxe's Book of Martyrs states, "Constantine so established the peace of the Church that for the space of a thousand years we read of no set persecution against the Christians unto the time of John Wickliffe."