If you want to go that way then the Western Roman empire wasn’t Roman either - Italy changed in profound ways as soon as Rome connected with Magna Graecia (i.e. Sicily and the sole of the Boot) and got its cultural appropriation on.
E.g. the most famous and lavish representation of Alexander the Great is not in Macedonia - it’s in Pompeii, because he was idealized in Rome as a prosperous go-getter. Roman architecture, philosophy, arts, military, religion… all got “Greeked” at that point.
Any love for the Empire of Trebizond? The remnant of the remnant, lasted marginally longer than the Empire of Nicaea that retook (then lost) Constantinople.
I’ll see your Empire of Trebizond and raise you a Principality of Theodoro … that lasted another 14 years!
Remnant of the remnant of the remnant … arguably, the “last of the Romans”. 
The name for the Russian emperor was “czar,” which is obviously derived from “Caesar.”
As was the German “Kaiser”.
That shit got around!
Well, the original “Kaiser” was the Holy Roman Emperor, whose empire was largely Germanic.
A lot of nations regarded themselves as the true heirs to the Roman Empire.
Heck, there are still a few tens of thousands remnant Greek speakers in Apulia and Calabria.
I disagree, because…
…I don’t but this premise.
IMHO the political continuity, including the dominance of the eastern Greek culture, surpasses the differences. Byzantium was a rump Roman empire, but still the Roman empire in this view.
Which I admit I’m not 100% dogmatic on :). I’m at least 25% playing Devil’s Advocate here. But like I said above I do lean towards this side of the argument. I think you can reasonably argue either side of the debate - in thyis case I think we are less in GQ than GD territory.
Ah, but Justinian’s reconquest was not a complete fiasco. He did firmly secure the cash cow of North Africa. A largely non-Greek area that rescued the empire from its dire straits under the usurping Phocas. You’re too early IMO ;).
Personally I go with an amorphous period of late-Heraclius/Constans II, somewhere between Yarmuk in 636 and the first invasion of North Africa of 647-648, when the Eastern Roman empire was effectively shorn of most of its major extremities ( Egypt, Syria, North Africa ) outside of southern Italy.
Yup, my point exactly. 
You don’t? I thought you were okay with naming a dividing line. 
Fair enough.
Way I see it, the problem with this reasoning is that the end products very cleraly are not “Roman” by anyone’s count - like I posted in jest above, claiming Byzantium = Rome arguably leads to claiming The Principality of Theodoro = Rome. There is obviously a “line”, the real argument is “where is it drawn”.
Fair enough, not wedded to any one date. My real point is that, *at some point *, Byzantium ceased to espouse or embody a credible vision of a universal imperium (if the sort that characterized “Rome” more than anything else) and became, in effect, just another country (Greek and Orthodox), with just another king - using “Roman” titles much in the same way as two-bit third world nations nowadays call themeslves “the democratic republic of X”.
Yes, but was he funky?
Here’s a series of maps with the Roman Empire outlined each century, but let’s pretend that it doesn’t say “Roman” and pretend that we don’t know if it is Roman or Byzantine or whatever – let’s call it the Mystery Empire. Euratlas Periodis Web - Map of Roman Empire in Year 600
I’ve linked via the map for 600 A.D. When you look at it, it’s obviously a huge empire of some sort, covering the Mediterranean and much of Italy, but lacking most of what is now Western Europe.
Let’s start from 600 A.D. and move backwards in time back to 1 A.D. If you did not know where the empire originated, there’s very little to lead one to believe that it originated in Rome.
Now let’s move forward, one century at a time, with particular attention given to 400 A.D. and 600 A.D. maps, for in that period a lot of the mystery empire was lost, but what remained was still was one hell of a large empire. As we move forward through the centuries, a large part of the boot of the Apennine Peninsula was part of the mystery empire in the 1200 A.D. map. Thereafter, it is pretty much a downhill slide for the Mystery Empire.
Here’s where it gets interesting. Let’s jump over to a map some sort of empire’s territory in 500 B.C. http://www.timemaps.com/history/ancient-greece-500bc Have a boo at the boot, then go back to the 600 A.D. map – there is a remarkable coincidence. Is that the territory of our Mystery Empire? Did our Mystery Empire arise out of Greece and later shrink back to Greece before disappearing all together? Of course not. We know that from well researched history, but it makes for an interesting hypothetical.
Perhaps, however, there is more to the hypothetical than meets the eye. Yes, the Romans conquered the Greeks, but when Rome was just starting to become a power, Greeks were their southern neighbours and trading partners, with tremendous cultural influence across the region. The Roman language was Latin, but Roman writing developed from the Greek alphabet. The Roman pantheon of gods was scooped from the Greek pantheon. Roman high culture of arts and letters grew out of and doted upon Greek high culture, particularly philosophy.
I submit that what we should be looking at is a Greco-Roman world, which started in Greece and spread throughout much of the Mediterranean through trade and colonization, and was particularly influential during its classical and Hellenistic periods. Most Greeks were Roman citizens more than a quarter of a millennium before the fall of Rome.
There was no single, sudden, permanent split in the Roman Empire into east and west. There were times when any pretty much everyone, their grandmothers and their dogs became emperor in quick succession – the soldier emperors. There were times when there was more than one Emperor at once – the Tetrarchy, which formed an imperial college in which the prime players were the eastern and western emperors. Licinius was Augustus in the west, and then later Augustus in the east. Constantine later to became Augustus of both, but seven emperors later, there were again separate emperors for East and West. The bottom line is that there was one empire, with rulers emerging out of just about anywhere, and with rule often being split geographically between east and west. Note that the last sole emperor, Jovian, was succeeded in the east by his son Valens (who was killed fighting the Goths in the east), and in the west by his son Valentinian. As people from the north continued to migrate south, the western part of the Empire eventually fell, but note that I am calling it the western part of the empire, not the Western Empire, for really it was one empire with eastern and western emperors.
Let’s have a look at the fall of the western part of the empire, almost a couple of hundred years after Rome was no longer the western capital (the first move had been made when Diocletian established the Tetrarchy). The second last emperor in the west was Nepos, who was put there by his uncle, the eastern emperor Leo I, and then proclaimed emperor by the Roman Senate.
Nepos was deposed by Orestes (previously Attila’s envoy to the eastern Emperor Theodosius II) who set up his young son Romulus Augustus as western emperor. In the east, Emperor Zeno had been deposed by Basiliscus, who in turn was deposed by Zeno, so neither had the ability to do much about what was going on in the west. Odiacer forced the child emperor to abdicate, and the Roman Senate petitioned Zeno to make Odiacer a patrician to administer the western part of the empire on behalf of Nepos, which Zeno did. It’s important to note that where there had been two emperors, there was now one – the remaining emperor was not the emperor of the east, but rather was the emperor of the entire empire, as shrunken as it was.
After a few years, Zeno then had Ociacer removed by Theoderic, an Ostrogoth who had been raised in Constantinople, and who was made a patrician and sent to drive out Ociacer. Although Odiacer and Theoderic were essentially viceroys of the Emperor, they pretty much ruled as kings in their own kingdom. About a decade later, Emperor Justinian I’s military right hand man Belisarius re-took the Ostrogoth capital and was offered the title of Western Roman Emperor, but instead reclaimed it for the Empire. Over the next few years, there was a lot of back and forth, with Rome changing hands several times, but ultimately Justinian I prevailed. Eventually, he took back control of much of the Roman Empire. Here’s a map that shows the fullest extent of the Empire in his time: File:Justinian555AD.png - Wikipedia .
Now we all know how this eventually played out. The Empire shrank back into the east, and after hundreds of years, the Ottomans defeated it. The last holdout was Byzantine garrison at Salmeniko Castle in the Byzantine Despotate of Morea in July 1461. Where would that be? Peloponnesian Greece.
That Mystery Empire was one empire, not two. Over time it changed, both geographically and culturally, but it was continuous, and although it was the Roman Empire due to Roman conquest, I sometimes wonder if it might better be characterized in a much broader sense as the Greco-Roman Empire.
Just a nitpick, but it was Irene who’s ascension led Pope Leo to crown Charlemagne Emperor, not Theodora. Theodora, for all her influence on Justinian and for all the suspicions that she ruled through him, was never Empress regnant in her own right.
That’s why the American Empire is not American. It is Canadian, thanks to its cultural appropriation of that young amped-up warrior Justin Bieber. We look forward to receiving your tribute.
If contract lawyers are to be trusted, then it’s Charles IX of France who bought what was assumed to be clear title. Andreas Palaiologos - Wikipedia
Correct. I am filled with shame, and with your agreement I will henceforth commit seppuku.
(in my defence all these emperors called themselves either Leon or Constantine, and half of their wives styled themselves Theodora, I had a 50/50 shot of getting it right :p)
… which brings the story full circle.
No, that’s the Ship of Theseus.
I kid, I kid. And I take your point, but I think you overstate a few things. For one, Greek was a major, major language in the “Western” Roman Empire for centuries before it nominally fell - long before the division into East and West, actually. It was regarded as the language of learning, culture, even diplomacy, and Roman elites prized Greek fluency. Did the role of Greek change in the Byzantine Empire? Sure, but not so categorically as you seem to suggest - nor did Latin die out. The Byzantines were an empire in the classic sense - polyglot, multiethnic, and with multiple major religions. (Yes, Christianity was the state religion - but that was true of the Western Empire, again, for hundreds of years before the east/west division).
As to institutional and economic change - in 1789, only white men could vote in the United States. And slavery was legal. And we were primarily an agrarian economy. Do you believe that the modern United States is not actually the same country as that extant in 1789? That’s not a rhetorical question, BTW - I consider it reasonable to argue that the United States is actually a pretty young democracy, insofar as Jim Crow kept huge portions of the population under a brutal authoritarian regime.
Really, it’s the cultural change combined with the essential contraction of focus. What made Rome uniquely “Rome” was its legitimate pretentions to universal empire - more than simply speaking Latin, or being based in Italy.
The Gothic Kingdom of Italy was likewise “not Rome”, despite the fact that they kept much of the administrative apparatus of “Rome” intact (ironically enough, largely wrecked by Justinian’s attempt to ‘re-acquire’ Italy). Why would I say that the Gothic Kingdom was “not Rome”, despite the “Ship of Theseus”-like change from the late Roman Empire to the Gothic Kingdom (after all, having Germanic leaders, and armies, was hardly anything new for “Rome”, right? And it was based in Italy - including actually owning the City of Rome itself - and largely kept late Roman administration running - the Goths certainly weren’t out to ‘wreck civilization’, they just wanted to run it).
I’d say that it ‘wasn’t Rome’ mainly because their horizons and interests were different. They though of themselves as a local kingdom, not as the universal empire. And after some time, so did Byzantium - which, combined with the cultural change, made them ‘more like unto’ a local nation-state, and ‘less like unto’ the Roman Empire.
This I would dispute. Right up until the end, the people in Constantinople thought of themselves as the Roman Empire and believed that they were special because of it. They believed they had a legitimate claim to all of Europe, North Africa, and the Middle East.
Right up to the end? Does this mean that the Principality of Theodoro was also “Rome”, maybe the last Roman territory? Or that poor Andreas Palaiologos was, in fact, the last Roman Emperor? (Well, as we know, he did live in Rome … ).
To my mind, the issue is not whether they “believed they were special” - no doubt they did, as inheritors of a great legacy - but the cold, hard reality: the Byzantines, particularly “right up until the end”, really did not have any realistic ambitions beyond those of a purely local kingdom. There was never any prospect that the Byzantines, after a certain point, were ever going to re-create a “universal imperium” - certainly not under the leadership of Mr. Palaiologos, passing his time away on charity in Rome, making himself agreeable to the local Roman nightlife, etc. And arguably, for centuries before him.
The Turks had a better claim than they did to that one thing that made “Rome” different - a real ‘universal empire’.
To answer the question in the OP - this is basically why Byzantium is not simply considered “Rome”. It is a lesser, successor state, of which there were several. They had the best claim for the legacy, but after a point (and reasonable people can disagree exactly when), they were no longer an active candidate for a universal empire, centre of civilization itself - which is the one reason above all others why people distinguish “the Roman Empire” from other, contemprary and successive states.
In sum, they had history and legacy, but (eventually) lacked the substance. They became a local, Greek kingdom.
