Why were the Mongols so effective? | World History | Khan Academy

The question before us today is why were the Mongols so effective? How do they manage to take an area starting around here and over the course of 20 years, during the reign of Genghis Khan, from about 1206 to 1227, expand from this little part of Siberia, just south of Lake Baikal, all the way into Central Asia? This is what the Mongol Empire looked like in 1206, and this is what it looked like in 1279. This here is Genghis Khan's time, and this here is around the reign of Kublai Khan.

So, what enables a spread of territory on this scale in such a short time? You know, the Mongols were not a centralized state; they weren't a centralized empire. They were a band of traveling horsemen. How did they end up taking this much land? The story of the Mongols is a story of a non-state actor overcoming state actors, of a decentralized power becoming centralized eventually.

What I want to talk about in this video is three reasons why the Mongols were so effective in beating established empires, and then we're going to talk about some of those follow-on effects.

Reason one why the Mongols were so effective was planning, what we might call logistics. When Genghis Khan—let me pull up a picture of good old Genghis—when Genghis was declared emperor or great khan of the Mongols in 1206, one of the first things he did was reformat the army. He swept away tribal affiliations and favoritism. If you were good, you got to have a higher position; if you were bad, you didn't. This meant that ordinary people within the Mongol army felt that they could have a measure of social mobility if they performed especially well in the army, and this made them very committed and very loyal.

Reason number two: the Mongols were extremely adaptable. So, we're talking about a group of horsemen here, right? These are the Mongols attacking a group of Chinese soldiers. What they were used to was mounted combat against mounted opponents. What they weren't used to was attacking major cities and holding them or even trying to get major cities to break. But the adaptability of the Mongol army meant that as they conquered new territories and as they fought and won and lost in various regions of Asia—so, for example, as they started conquering the Western Jia here—they learned siegecraft, and that's the art of attacking walled cities and castles. It's a completely different style of combat.

What it involves is sitting outside of a city and waiting to starve out the inhabitants. Part of it involves using these things called siege engines. So this here is a kind of catapult. You can see here the rocks; the Mongols are waiting with their archers here. The opponents have arrows as well, but they're flinging rocks into the city in order to force a surrender. The Mongols didn't really have this technology or these tactics when they began their military campaigns, but as they rolled through Central Asia, they picked it up, and then they continued to use those tactics as they swept westward.

Now, the third reason that the Mongols were so effective is because they were terrifying. Even though they mastered siege warfare in the beginning, at least the Mongols were not prepared to hold a city once they had conquered it. So there are stories, especially from the conquest of the Western Jia and the Northern Song and the Khwarezmian Empire over here, that tell of the Mongols winning a battle and then sweeping in and murdering everyone, just pulling plunder from corpses and just looting the entire city and leaving nothing standing—because the Mongols weren't especially interested, at least early in the—we're talking about the period of Genghis Khan's life here, so 1200s to 1220s. They weren't especially interested in governing; they wanted to hold territory and get tribute and get money, but they weren't especially interested in running an empire. It actually made more sense to them just to slaughter everybody and take their things.

Now, it got to the point that this reputation for fearsomeness got so powerful that some cities would just give up and surrender the moment the Mongols arrived. So those are the three main reasons that comprise Mongol effectiveness against settled states: they were very good at planning; everybody rode in their armies; they could move very quickly; the Mongols were extremely adaptable—every time they lost, they learned something from the people they lost to—and that meant that they picked up new technologies like siege warfare, and they were absolutely terrifying. Since initially, the Mongols didn't know what they were going to do with a conquered city besides loot it, they just killed everybody.

That reputation really allowed them to conquer a lot of land very quickly. We see, out of the Mongol conquest, there are many follow-on effects, but one of the chief ones is something called the Pax Mongolica, or the Mongolian peace. If that phrasing looks familiar to you, it's because it's similar to the Roman peace, the Pax Romana, and the Chinese peace, the Pax Sinica of the first century CE. This is 1100 years later, but the same principle applies.

What happened was, with all of this territory conquered under one ruling power, it became safe to travel from one end of the empire to the other. Indeed, this is exactly what Marco Polo did when he set off from Venice and made his way eventually to Beijing. That would have been around this time. Marco Polo's book, "The Book of the Marvels of the World," was published in 1300. Marco Polo was this Venetian trader and adventurer who traveled extensively throughout Asia.

So that's one result of the Mongol conquests: this Mongolian peace. Now, I should say that this Mongolian peace came at a terrible price. We were talking about the terror of the Mongols; that's a for real thing; they murdered millions of people. However, what would come after the Mongol conquest, as a result of this peace, would end up killing even more people than the Mongol conquests itself.

So this pacified region, this Mongolian peace, led to increased trade throughout East Asia and reconnecting it to Eurasia and the Arab states. That would result in the exchanges of new ideas and new technologies and new agricultural techniques. However, as trade always does, it also results in the exchange of diseases. So out of the Mongol homeland, in fact, comes this illness called the Black Plague or Bubonic Plague, and because of the stability of trade that had been established by the Mongol peace, it makes it so much easier for this illness to sweep across Asia and Europe, killing even more people than even Genghis Khan could have achieved during his lifetime.