The Official Christianization of the Empire, 312 B.C.E.—c. 540 B.C.E.
1. 312
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
2. 313
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
3. 325
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
4. 361–363
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
5. 391
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
6. 451
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy
7. 540
-------- Julian the Apostate tries to reinstate traditional religion as official state religion Benedict devises his rule for monasteries Council of Nicaea defends Christian orthodoxy against Arianism Constantine wins the battle of the Milvian Bridge and converts to Christianity Religious freedom proclaimed in the Edict of Milan Theodosius I makes Christianity the official state religion Council of Chalcedon attempts to forge agreement on Christian orthodoxy