Color in every country that has, at some point in its history, officially claimed to be the true heir of the Roman Empire, and the map stops looking like Europe and starts looking like a family argument that never ended. A wide red band runs from France and Spain through Germany and Switzerland, down across Italy and the Balkans, into Turkey, and up along the Baltic. Rome fell in the West in 476 AD. It never stopped being claimed.

The first and strongest claim didn't even need reinventing — it just kept going. The Eastern Roman Empire, ruled from Constantinople, never fell in 476; its citizens called themselves Romaioi, Romans, right up until the Ottomans took the city in 1453. What historians label "Byzantine" was, to the people living it, simply Rome with a new capital and a different language of government. Nearly a thousand years of unbroken continuity — longer than the "fall" of Rome is usually taught to have mattered.

The West, having actually lost the thing, wanted it back more badly. On Christmas Day in the year 800, Pope Leo III crowned the Frankish king Charlemagne "Emperor of the Romans" in St. Peter's Basilica, reviving a Western imperial title that had sat vacant for over three centuries. It was a legal fiction with enormous consequences: Charlemagne's successors kept the label alive, and by 962 it had solidified into the Holy Roman Empire, which Voltaire would later mock as neither holy, nor Roman, nor an empire, but which nonetheless organized Central Europe for the next 844 years. German emperors were crowned with Roman rites, carried a Roman-style eagle, and dated their legitimacy back to Augustus, even while ruling a patchwork of German-speaking principalities that Augustus would not have recognized.

Then Constantinople actually fell, and the claiming got even stranger. Mehmed II, the Ottoman sultan who conquered the city in 1453, promptly styled himself Kayser-i Rum — Caesar of Rome — arguing that whoever held the Roman capital held the Roman title, full stop. Moscow made the opposite argument at almost the same moment. A monk named Filofei wrote to the Russian tsar around 1510 that Rome had fallen once to heresy and fallen twice to the Turks, and that Moscow was now the "Third Rome" — and there would be no fourth. Ivan III had already married a Byzantine princess and adopted the double-headed eagle as his own symbol; his grandson Ivan IV took the title tsar, a Slavic contraction of Caesar. Russia's claim to Roman succession still echoes in the word Russians use for their own historical emperors today.

By the time Napoleon crowned himself in Notre-Dame in 1804 — the moment behind this week's header image — the playbook was five centuries old, and he followed it almost exactly. He revived the title "Emperor," adopted Roman eagles as his legions' standards, restyled the French Senate on classical lines, and had himself painted, sculpted, and depicted on coins in the manner of a Caesar. It worked as propaganda precisely because European audiences already understood "Emperor" as a specifically Roman word, one that outranked mere kings.

The claiming didn't stop with the nineteenth century. Mussolini's fascist regime built an entire aesthetic — the fasces, the straight-armed salute, the phrase Mare Nostrum for the Mediterranean — around explicit Romanità, the idea that Italy was resuming an interrupted imperial destiny. Even Bulgaria and Serbia, in their medieval empires, adopted the title "tsar" for exactly the same reason Moscow did.

What makes the map worth staring at is less any single claim than the pattern underneath all of them: for a millennium and a half, "Rome" functioned less as a place than as a kind of institutional currency, one that new powers minted for themselves because the alternative — admitting there was no ultimate legitimate authority at all — was harder for medieval and early modern people to accept than borrowing someone else's expired brand. Charlemagne, Mehmed, Ivan and Napoleon never met each other and shared no army, language, or century. What they shared was a recognition that the fastest way to make raw power look like rightful power was to attach it to Rome's name, and that the surest sign an empire understood its own fragility was how loudly it insisted on the ancient one behind it.

Sources: Peter Heather, The Restoration of Rome: Barbarian Popes and Imperial Pretenders; Judith Herrin, Byzantium: The Surprising Life of a Medieval Empire; Encyclopaedia Britannica, "Holy Roman Empire" and "Third Rome"; Serhii Plokhy, The Origins of the Slavic Nations.

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