Fall of the Roman Empire | World History | Khan Academy

• [Instructor] In the last video, we talked about the first 200 years of Rome being an official empire, starting with Augustus in 27 BCE, going all the way to Marcus Aurelius. That time period is referred to as Pax Romana, Roman Peace. It's a relatively stable, relatively peaceful time for Rome.

Now, all of that is relative. If you're one of the tribes that are still fighting with the Roman legions, if you're one of the roughly 1/4 to 1/3 of the population that is a slave, you might not view this as such a good time. But things only get worse after the death of Marcus Aurelius, who's viewed as the last of the five good emperors, so to speak. His son, Commodus, takes over, and Commodus is the beginning of a succession of emperors who are less and less competent.

The Empire becomes more and more corrupt, less and less stable, and things really come to a head and start to decelerate even further, or I guess accelerate downward even further, in 235 CE when the emperor Severus Alexander is assassinated. This throws the empire into a 50-year crisis called the Third Century Crisis because it happened in the third century. Over these 50 years, there are 26 claimants to emperor.

The empire is temporarily split into three different states. There are attacks from the east from the Sassanids, the Sassanian Empire; they're the successors to the Parthians. You have attacks across the Rhine and the Danube from Germanic tribes. All of that makes this a very unstable period for Rome. Now, the Third Century Crisis is considered to end in 284 with the ascension of Diocletian, and Diocletian is viewed as a somewhat, or a reasonably strong emperor.

He's known as the last emperor that really persecuted the Christians because they didn't follow the Roman religion; they did not worship the emperor as a god. But he's also, or maybe he's most famous for splitting the empire. He decides that probably one of the main causes of the Third Century Crisis is that the empire has gotten too vast. It has too many borders. It's hard for one emperor to administer the whole thing, so he splits it into East and West from an administrative point of view.

They don't become separate empires, but he decides that he is going to rule from the East and that he will have a co-emperor who rules from the West. Not only does he set that up, but he sets up what's called a tetrarchy. Beyond himself and his co-emperor, they each have a second-in-command that if any one of them were to die or would have to retire somehow, that second-in-command could take over.

Once again, this is to address some of the issues of the Third Century Crisis where the wars for succession, and this isn't just during the Third Century Crisis. We've seen it in multiple videos. Rome is famous, even during the Pax Romana, for these really ugly succession battles. But as we'll see, the splitting of the empire into East and West, even though it started as an administrative thing, over time it's going to become a real split and they're going to turn into two different empires.

Now, after Diocletian, you have another significant emperor. You have Constantine, and Constantine is known for many things. Maybe most famously, he embraced Christianity, as opposed to Diocletian who persecuted Christians. You have the Council of Nicaea and the Nicaean Code where there's now a uniform church doctrine around Christianity. He has the Edict of Milan, which makes Christianity legal under Roman rule.

Maybe most famously on his deathbed, he gets baptized. He becomes the first Christian emperor. He also moves the capital to, officially moves the capital of the entire empire to what at the time was Byzantium, but then he renames it to Constantinople, named after him. Now, it was still one unified empire, even Diocletian who co-ruled with a co-emperor. He had veto power over the emperor to the West.

Now, as we get further into the fourth century here, and especially into the fifth century, we'll see that the empire further and further fragments, and gets diluted, and really just breaks down. One major factor in that breakdown is in the fourth century, in the fourth and fifth centuries, you have a group called the Huns coming in from Central Asia, coming in from Northern Europe right over here, and they are fierce, nomadic conquerors.

They're so fierce that they start pushing more of the Germanic tribes across the Rhine and the Danube. A lot of these Germanic tribes, at first, even though their history has been fighting the Romans, a lot of them try to seek refuge in the Roman Empire, and they're given refuge in the Roman Empire. But while they have that refuge, they're treated very, very, very badly. All of that comes to a head in the, well I guess you could say, the last quarter of the fourth century with the Gothic Wars.

The Gothic Wars really have a decisive battle at Adrianople, originally Adrianopolis, named after the Emperor Hadrian. At Adrianopolis, at Adrianople, the Gothic tribes in particular, and when we say Gothic, we're really talking about Germanic tribes. This one in particular, as you can see from this legend right over here, this is the Visigoths, or Western Goths. They're able to decisively defeat the Eastern Roman Emperor Valens. He's actually killed at Adrianople, and then the Visigoths just continue to hang out here in the Roman Empire.

They continue to move forward. In 410, they're able to actually sack Rome, and they eventually settle in the Iberian Peninsula and in Southern Gaul. Now, after the Battle of Adrianople, you have another significant emperor, Theodosius. Because what you'll see is that Diocletian persecuted Christians, Constantine now embraces Christianity; he becomes a Christian; he says Christianity is legal.

Theodosius now, right as we are about to enter into the fifth century, he makes Christianity the official religion of the Roman Empire. So in roughly 100 years, the Roman Empire went from persecuting Christians to making it the official religion and actually going the other way, starting to persecute some of the pre-Christian religions or rituals.

The other thing that happens as we enter into the fifth century now, as we go into the fifth century, you have the capital of the Western Empire is moved from Rome to Ravenna. With the idea, the emperors see all of these Germanic tribes; they feel threatened by them, that Ravenna is easier to defend. It's surrounded by kind of marshy, swampy area.

The other thing of note about Theodosius, and as we move into really the last century of the Western Roman Empire, is Theodosius was the last Roman Emperor to rule all of Rome. After that, the East and West are going to be ruled essentially independently. They're essentially going to be separate empires. Then, as we get into the fifth century, we already talked about the Visigoths sacking Rome; then in 455, you have the Vandals, which is another Germanic tribe that was similarly originally pushed out by the Huns.

You see them in blue right over here. They make it down the Iberian Peninsula to North Africa. They eventually get to Carthage, and they become a little bit of a naval power. They eventually are able to, in 455, sack Rome as well. So Rome is really taking a hit multiple times.

Finally, the end of the Roman Empire, or the Western Roman Empire that most historians consider the end of the Roman Empire, is when the Germanic ruler General Odoacer, or Odoacker depending on how you pronounce it, is able to oust the emperor in Ravenna. So then you have the official, and just to be clear, this is, let me write, Roman Empire. Odoacer is able to essentially end the Western Empire as we know it.

After that, the Western Empire becomes more and more fragmented into these kingdoms that are ruled by essentially Germanic kings, and then we are now entering into the Middle Ages. Now, the big question that historians have a lot of fun thinking about is why did all of this happen? Why did the Roman Empire fall?

Before we even talk about why it fell, we should give them a little bit of credit. Even in this video where I talk about the fall of the Roman Empire, I'm covering 300 years of history, and if you start with the founding of the republic until Odoacer takes over Ravenna, ousts the emperor, we're talking 1,000 years. Most civilizations, most empires don't last anywhere near that long.

So to some degree, it's surprising that it lasted so long. But in terms of the causes of its decline, we've talked about several of them in this video. The empire got divided. The East and West stopped viewing themselves so much as the same empire.

Trade sometimes broke down. They didn't support each other militarily. The Eastern Empire was generally stronger, so it allowed invading tribes to focus on the weak point in the West. Some historians would say that the Roman Empire stopped expanding, and it needed that expansion in order to keep getting more land and more slaves that really drove its economy.

One major factor probably was the Huns that caused this great migration in the fourth and fifth centuries. It caused the Germanic tribes to cross the Rhine and cross the Danube and become either settled as part of the Roman Empire or threatened the Roman Empire.

Another theory, and all of these are probably contributors, is that as the Germanic tribes settled, they actually became more and more part of the Roman military. Some of them were officially part of the military; some of them were mercenaries, soldiers for fortune, paid soldiers. You can imagine their allegiance to Rome was not as strong.

Some folks say Christianity may have been a factor; that the empire might have lasted, especially when people were doing what their traditional rites, rituals, they worshiped an emperor. But now Christianity wasn't about worshiping an emperor anymore. A lot of people think it's corruption, instability, and we've talked a little bit about that.

It could've been invasions, not just from the Germanic tribes and the Huns, but also the Sassanids on the East. So I'll leave you there, and to think about what was the cause or maybe what allowed the Roman Empire to survive for so long?