The Byzantines spoke Greek, did not rule in Rome nor were they Roman Catholic, thus they were not Roman. That is the basis for all arguments that dismiss the title of the Eastern Roman Empire. In a complex world, its history becomes complex as well. Constantine the Great created a second capital for the Romans in the 4th century, it was called New Rome and then Constantinople after its creator Constantine. Its creation was because the Empire was too large and to spread out. The location he chooses was excellent for defense and for trade and taxation. At the time of its creation, it had no enemies close by, just conquered lands of the Romans. Originally the population spoke Latin, that changed after the revolt of Heraclius in the early 7th century. As time Changed, the city of Rome fell. The Empire changed and new ones appeared in it place but the Empire of the Romans still stood in Constantinople. In the west it was referred to Res Publica Romana, In the mid-8th century the popes of Rome made a change, in the west, the empire became known as Graeci. That is the earliest test to the empires name and Emperor’s title. In the 9th century the real push to remove the title from the Eastern Roman Empire, they began to question if the Eastern Emperor had the right to call himself Emperor of the Romans. This came about as the Germans powers were drawing heavily on Roman prestige. They saw the Eastern claim to the title as a major obstacle. As the title Graeci was used with more frequency, it became known as a name with many negative connotations, treachery, excessive sophistication, love of luxury, verbal trickery and cowardice. During the time of the Empire, they themselves called it the “Roman Empire” and their enemies called it “bilad al-Rum ( Lands of Rome) In the West It again changed, Western literature began calling the Emperor, Emperor of the Greeks and Emperor of Constantinople, also less frequently used, The Low Empire, The Late Empire, The Roman Empire. These remained in usage until long after the fall of Constantinople. The 19th Century was the first regular usage of the word Byzantine. Now the first usage of the word Byzantium in an Academic sense came from the title of a commissioned book of translations, the author was a translator Hieronymus Wolf the work was” Corpus Historiae Byzantinae” ( 1557-62) In it he makes his contempt for the Empire known. “I am surprised, not sorry, that such dregs and bilge water of a iniquitous people so long remained unmolested and were not conquered earlier.” So the word Byzantine was born after the empire and not as a compliment, just another way to disassociate it from Rome. At this point the word Byzantine was not in regular usage to describe the Empire, the real time when this word becomes common is in the mid-19th century. No one knows for certain what created the movement of referring to the Romans as Byzantines, it seems to be a buildup of modern politics, racism and theological conflict. Some have surmised it was brought into use after the Modern Greek state in 1820 to deny the Greeks their history and claim to their old territories. In other theories it was to prevent Russia from creating a new Puppet state in the Ottoman territory. This story is more complex, but it again had to do with the Modern Greek state. Regardless, the results are the same, with the name Byzantine in leaves an empire without a known heritage, it was based on the original long forgotten town the city of Constantinople was built on. It is interesting that this question is being asked in multiple books, now Byzantium is a name of convenience to represent the time. For Numismatics Byzantine begins at the coin reform of Anastasias, for some it is the change of language after the revolt of Heraclius and for some The Roman Empire ended during the fall of Constantinople in 1453 so Byzantium as an empire never existed. My primary sources for this write up were two newly published books, both are filled with abundant info, far more detailed than my brief write up. Romanland Ethnicity and Empire in Byzantium by Anthony Kaldellis The Invention of Byzantium in Early Modern Europe Edited by Nathanael Aschenbrenner and Jake Ransohoff I have always been curious on the renaming, I thought I would share the story. I realize it won't change anything, but the truth is always interesting.