It is even more fun to put this into historical context. Diocletian [244-311] ruled 20 years from 285-305 AD and then abdicated to his Son-in-Law, Galerius. A mere single YEAR after his abdication, while he was still alive, Constantine I (the Great) [272-337], became Galerius' heir.
In the consolidation of his power and in ending the shared rule of the Roman Tetrarchy, he defeated his rivals in a series of civil wars [312-24], and made all religions equal to that of the Roman Gods with the 'Edict of Milan'! While remaining Pagan for most of his life, his mother was a devout Christian and he converted to Christianity on his deathbed in 337.