But that isn't your point in your blog post is it. You aren't simply referring to when historians for sake of convention and neatness like to stop talking about the Eastern Roman empire and start talking about the Byzantine empire (because of the use of Greek, I believe).
You're clearly comparing it with the centrality of Islam to Europe, and pretending that this largely arbitrary convention is telling us somehow that the Christian East only sprang into being then. Heraclius was another Eastern Roman Christian emperor - and there'd been one of those for something like 300 years beforehand.
But that isn't your point in your blog post is it. You aren't simply referring to when historians for sake of convention and neatness like to stop talking about the Eastern Roman empire and start talking about the Byzantine empire (because of the use of Greek, I believe).
You're clearly comparing it with the centrality of Islam to Europe, and pretending that this largely arbitrary convention is telling us somehow that the Christian East only sprang into being then. Heraclius was another Eastern Roman Christian emperor - and there'd been one of those for something like 300 years beforehand.