Gaius Flavius Valerius Aurelius Claudius Constantinus (Constantine the Great) was born between in 272 or 273 A.D. in the city of Naissus, which is now the city Nish in Yugoslavia. His mother was a poor innkeeper, but a myth says that she was a British princess. This is only because Constantius, Constantine's father, spent many years in England.

During his childhood, Constantine spent most of his time in the court of Diocletian. Diocletian kept him there so that Constantius, who was a great military leader, would cooperate with him and not threaten his rule.