Housfrau lets get some things clear because you mix up terms and concepts without understanding the distinctions between them In the middle Byzantine period Hellenes does not mean Greeks It is used to mean pagans Helladikoi does not mean Greeks either but the inhabitants of the theme of Hellas as the DAI uses the term Hellas of course means Greece and was the original core of the Greek world but it does not imply that Greeks lived only there Since Classical and Hellenistic times the Greek world was much wider than the original core GreeceHellas There was no ethnonym specifically referring to Greeks as such in Byzantine times at least not in the timeframe we are interested in You say that Only the language was Greek but this is all well yes except that language is one of the major markers of ethnicity This does not mean that a Romaios was a descendant of Themistocles just as it does not mean that I am a descendant of Alexander because I am speaking Greek Ethnic identity is mostly a matter of belief and culture All Byzantines were Romans Romaioi and in its most typical sense that term means a Christian Greekspeaking and culturally hellenized Byzantine subject That is what the Byzantine Greeks article refers to and that is pretty much what the brothers were If you had read the Byzantine Greeks article we wouldnt need to have this conversation