 A while back in my video on Korean, I said that Hangul was invented by the Emperor himself, Sejong the Great. As many people have since pointed out, however, Sejong was not an Emperor. He was a King. No one calls him an Emperor and I shouldn't have either. But that got me thinking, how exactly do you tell whether someone is a King or an Emperor? Like, I think we all think of different groups of people when I say these words, but these people and the countries they were in charge of seem pretty similar to me. Maybe the difference is that Kings have kingdoms while Emperors have empires, and a kingdom is a small nation state while an Empire is a much bigger multinational entity. And that fits most of the time, but by that logic, modern Russia should be called an Empire since it's both huge and contains a lot of very different cultural groups, while the Holy Roman Empire and the Byzantine Empire should be called Kingdoms because of how comparatively small and homogenous they were. But no one ever does either of those things. The truth is, which countries we call Empires and which we call Kingdoms is really arbitrary and tied up in what I think is some very interesting history. Like a lot of history stories, this one starts with the Romans. Latin, like most languages, had a word for rulers that held all of the power and passed it down to their kids. We call them Kings, their word was Rex. But for the first huge chunk of their history, the Romans defined themselves largely by the fact that they didn't have one. In Rome alone, did people make sure that no one person ever got too much power? So when eventually one person got too much power, he knew he at least needed to pretend he wasn't King or else he'd get stabbed 23 times. The result of this was that even though all of the power in Rome was concentrated in the hands of one person, and even though he usually passed this position on to his relatives, they never called this person a King. Either they were called Commander in reference to their position in charge of the military, which in Latin was Imperator, or they were called Kaiser, which was just their last name. Like, since all of the first few of them were related, they all had the same last name, so people started using that last name to refer to the office itself. After 476, when Rome lost control over the part of Rome that had Rome in it, for more than 300 years, the only people who called themselves Imperator or Kaiser were the people who we now call the Byzantines. After all, they saw themselves as Roman, and these titles had basically come to mean the person in charge of Rome. But around the same time, these titles also became more than that. Rome had been the biggest and most powerful country in the region by a lot for a long time, so Imperator and Kaiser started meaning person even more powerful than a king. And as such, Europeans started using them to refer to people outside of Europe who ruled particularly big and powerful countries. When referring to people within Europe, it meant leader of Rome. And when referring to people outside of Europe, it meant as important for those people as the leaders of Rome are for us. Because of this association with Rome and the ridiculous amount of prestige that comes with Rome, a lot of rulers over time have adopted one or both of these titles. The leaders of the Ottomans called themselves Kaiseri Room when they were placed to the Byzantines, the implication being that they were the new Byzantine Empire. To which the Russians responded, no, were the new Byzantines, and then they started calling their leaders Kaisar, or Tsar for short. In Western Europe, a Germanic king who in English we call Charlemagne claimed to lead the successor to the Western Roman Empire. He took both these titles, but speakers of German gradually stopped using the word Imperator as much, favoring Kaisar instead. And the leaders of Germany kept calling themselves that up until World War I, which is why in English we call this guy the Kaiser. Basically, the reverse happened in English. Imperator became our modern word emperor, while Kaiser we reserved for ancient Romans who were actually members of that family. We started pronouncing it Caesar though, because French. That was the status quo for a few hundred years, until Napoleon declared himself Emperor of the French, and once he started doing it, everyone started doing it. The Austrians started calling themselves Kaiser von Usterreich, the Queen of England decided that she was also the Empress of India, and the Regent of Brazil declared independence from Portugal and took the title Imperador do Brasil. All of this had the effect of taking away a lot of that successor to Rome implication that these words used to have. After World War II, the world was dominated by two main ideologies, liberal democracy and communism, and at least in theory, neither ideology was particularly fond of the idea of one person having all of the power, so today almost no one calls themselves Emperor. But we still call lots of historical entities Empires and the people in charge of them Emperors. Usually we do this either when they call themselves Imperator or Kaisar, or words derived from them, or when it's just a really big country. Although there are some weird exceptions, but even if all of this put together makes the distinction between King and Emperor seem kinda arbitrary, everyone still just goes along with it, because if everyone calls someone by one of them and you use the other, you wind up looking kinda stupid. Trust me, I learned the hard way. It feels wrong to have the full credits about the song for short of videos, but people got mad at me last time when I didn't put the patrons on the screen for very long, so I don't know what to do here.