How Mongols conquered China | Jack Weatherford and Lex Fridman

So the great thing left that Chinggis Khan said on his deathbed was to finish conquering China. You know, that was the great objective. So Kublai was going to fulfill this, and they didn't know how. The great wall of ships was protecting the Southern Song. This huge Yangtze River was so wide. The ocean on the side—all of these things were protecting them.

So he had one of his very smart generals named Aju, who was a real Mongol, but he was also able to think in an innovative way. He was the grandson of Subadai, and he went with his father, Uriyangkhadai, on the conquest of the Red River of Northern Vietnam against the Dai Viet people. They went down the river. They were trying to surround this Chinese territory. They were going to hit them from the north, from the west, and from the south. So they went down the Red River to conquer the Dai Viet. The Dai Viet moved their army up on the other side by boat, and then they had a whole corps of elephants. So they had the Mongols on one side of the river and the Dai Viet forces on the other side.

Uriyangkhadai was a smart man, not a genius, but smart. And he already knew from campaigns in Burma that the only way to rout the elephants was with flaming arrows to defeat them. That was it. But he recognized that they came up on boats. Mongols didn't like boats. They crossed the river on a goatskin. They wanted to do something organic. A boat was like a cart. A cart belonged to a woman. It was a floating cart. 'I am not going over on a floating cart. I'm going to ride a goatskin across the river.'

So he assigned one detachment: 'You have to burn the boats so the Dai Viet cannot escape when we rout the elephants.' Well, the battle, I mean, got started. The elephants are running wild. All kinds of chaos is going on. The group that's sent to burn the boats—they're Mongols. They want to go to war. I mean, why burn a bunch of women's carts? It's just not, you know, floating. So they go and join the battle. They leave the boats. Well, the Mongols won the battle, but the Dai Viet forces got on the boats and sailed back to what's now Hanoi. And then they evacuated the city, took all the food, everything out of the city, and they disappeared into the delta. The Mongols arrived, they conquered, quote-unquote, Hanoi, the capital city, and they had nothing.

They had nothing. They won every battle. They lost the war. They retreated. Aju was the son of Uriyangkhadai, and he saw all this happen, and he recognized the importance of water and boats. And so he knew, and he spent his time studying the Yangtze River and every little river around it and the cities. And the crucial thing he saw was the cities are heavily, heavily fortified on the land side because invasion comes from the land, and they expect this little line of boats to protect them on the water. And so their city walls are weak. The defenses are weak on that side. That's where we have to attack.

So they sent off to the Ilkhanate, to Persia, where Chinggis Khan—his uncle—was now dead, and his cousins were ruling there, or his nephews, we would say, or cousin's nephew. So they sent over engineers to build a special kind of trebuchet catapult, and they had to play around with it to adapt it for a boat because they were usually made for stable ground. But they adapted it for the boat and for throwing heavy things and also for some incendiary bombs. They developed it, and they attacked the first city; it fell. They attacked the next; it fell. They had something that was working. They worked their way down the Yangtze River, destroying city after city with this navy, and then the army would move in after the navy had broken down.

Catapult on a ship, but it's—yeah, we call it a type of shape for this type of catapult.

Yes.

Yes. Now it's a great weapon. It's like—it's no longer a woman's cart. It's a bow and arrow. It is a giant bow and arrow.

Where there's no army protection.

And they conquer their way down to Lin'an, the capital of the Southern Song. They've been in power for a long time, since 960, and now we're already into the 1270s. That's a long time. They are dissipated. They've had child emperors, they had imbeciles ruling, all kinds of things going on. And at this point, we have a child in command.

But Kublai makes a very strange move. He says, 'Okay, let's invade Japan now.' They think, 'What? We're fighting against the Song Dynasty.' And most people ascribe it to all kinds of things, but actually I think there was a great logic to it. One was he had abolished his grandfather's policy of 'defeat and destroy until they are no more'—that was the phrase that was used for their enemies—and he had replaced it with a kind of mercy policy. Try to incorporate them into your army if possible, but be merciful. He did not want to destroy, and he had a lot of defectors coming in. And because the Mongols prized people with skills, a lot of very clever people with shipbuilding and engineers, these people were flocking to the Mongols. Whereas the scholars were all hanging out in Hangzhou doing calligraphy and poetry and having contests over who could sing or paint or—I don't know what scholars do—but they were being scholars.

Yes. But actually, I think there's a very, very good reason for invading Japan. Several. The main one was to cut off the supply of sulfur. They needed it for gunpowder in the Southern Song. They lost their sources in northern China when they were driven out. They got it from Japan. It was a great source. But I think there were other reasons. If they could trade, they could also perhaps flee to Japan, and they didn't want that to happen. And then there's this idea of, you know, like 'kill the chicken to scare the monkey.' It's like, okay, we'll go do this, and then maybe they'll just surrender down there if they see us conquer Japan. Well, it was a total failure. You've got a bunch of ships that are mainly great on the river and ride along the coast, and you're crossing some treacherous water there, and the Mongols basically just did not know what they were doing. Okay, you can arrive with a trebuchet and you can throw grenades at the beach. It's not really going to do a lot of damage. It might scare a few horses, but you're not destroying cities. And the Japanese cities were more inland. They weren't there on the beach waiting for Mongols to come invade. So he failed in that invasion.

Samurai, yeah.

No, there was some fighting, and the samurai learned some very valuable things. The samurai had such a ritualized way of—it's like the knights of Europe.

Coming out with armor that had to be lifted up on a crane onto a horse, and I mean, it was just craziness. Craziness. The samurai almost at that point—you ride out in front of your enemy and you recite the story of your genealogy, right? Well, the Mongols, they have no use for that. They're there to fight. They're there to win. But on the other hand, this was unknown territory to them, and the weather did turn against them. But I don't want to give too much credit to the weather. I really think that the Japanese defeated them. The Mongols weren't well prepared. Their ships were not very good. They were defeated in the first invasion.

Oh, they did. They had some skirmishes or small battles on land. Yes, they did.

No.