Also, insofar as the Roman Empire was a thing of holiness, it was not the first Christian government, that was the Kingdom of Edessa, converted in 301 AD, the first Christian nation was the Kingdom of Armenia, converted by St. Gregory the Illuminator (who we venerate, as well as the Armenians) in 306 AD, and the Roman Empire was the sixth, under St. Theodosius when he finally banned Paganism and smashed the Altar of Victory around 390 AD (in the interim, Georgia and Ethiopia both converted to Christianity).
Now, St. Constantine the Great did embrace Christianity and legalize it under the Edict of Milan, but his heir Constantius was an Arian heretic, and Julian the Apostate was a Neo-Platonist; there was not another Christian Emperor until St. Theodosius, and it was only under Theodosius that the Roman Empire declared Christianity its official religion. Shortly thereafter it split into the Eastern and Western Empires, the Western Empire was overrun by Visigoths (who were Arian) and collapsed, and the Eastern Empire persisted until Turkocratia.
By the way there are a large number of Eastern Orthodox members of this forum -
@prodromos @jas3 @FenderTL5 @HTacianas - in the event we are making any mistake, our pious brethren will correct us, if we invite them to do so.