[Lightscreen]
[Ever since the Han dynasty brought the Western Regions under its administration and opened the Silk Road as the greatest commercial highway in the known world, the conflicts generated by Silk Road profits have been practically endless.
Now the question is: how profitable was the Silk Road, exactly?
Maybe the Parthian Empire would be the first to raise its hand: oh, you want to talk about this? We are suddenly not sleepy anymore.
Let's talk money.
The short answer: it was immensely, empire-alteringly profitable.
We are not talking about pocket change here. We are talking about enough wealth to fund armies, build cities, and make middlemen some of the richest people on the planet.
The most direct profit came from the goods themselves. Think of it like the world's most exclusive luxury market before there was even a concept of a global market.
The real MVP was silk. For centuries, China had a monopoly on producing high-quality silk. It was the ultimate status symbol in the West. Soft, comfortable, and capable of holding vibrant dyes better than any other fabric. Rome could not get enough of it. It was their most significant and constant import from the East.
What did the West send back? Fine Roman glassware, gold and silver bullion, jewelry, perfumes, and woolen textiles.
But here is the real kicker. You did not even have to sell anything to get rich on the Silk Road. You just had to own the road.
That is why the Parthians boldly lied to the Han imperial envoys. That is why they orchestrated elaborate deceptions. They did it for one simple reason. They sat at the chokepoint of that road and collected tolls from everyone passing through. Easy profit. No effort at all.
The Parthian Empire sat right in the middle of the east-west trade routes and became the ultimate middlemen. Their entire business model was basically a high-end toll road. By controlling the chokepoint, they could tax every single caravan that passed through their territory. Their tax revenue was so immense that the Roman historian Tacitus compared the Parthian treasury to that of Rome itself. That is a monumental compliment, as Rome was the economic superpower of the West.
Fast forward a few centuries, and the Kingdom of Gaochang raised its hand to enthusiastically agree.
Gaochang: big brother Parthia, we are speaking the same language right now.
After the Eastern Turks collapsed, every state along the Silk Road scrambled to send tribute to Chang'an. Face had to be maintained, and the Tang was the new big dog in town.
Gaochang was among the first in line.
This was Gaochang and the Tang's brief honeymoon period.
From Gaochang's perspective, all it took was a few imported Western dogs to make Li Shimin laugh, and in return, the Emperor bestowed the prestigious title of Princess Changle upon Qu Wentai's wife. It was an absolute geopolitical bargain!
And here is the best part: this is not just a joke. It actually happened.
In 631 CE, Qu Wentai visited Chang'an. Li Shimin was in a great mood and decided to be generous. He gave Qu Wentai's wife the imperial surname Li and the title Princess Changle. That was a huge deal. In Tang dynasty politics, getting the emperor's surname was like being adopted into the royal family. You could not buy that kind of status with gold. You could, apparently, buy it with dogs.
Western dogs, to be precise. The records mention them. Somewhere in the official archives of the Tang dynasty, there is a line about dogs being part of a diplomatic gift. Let that sink in. A kingdom's fate, a princess's title, all sealed with a few fluffy imports from the West.
From Li Erfeng's perspective, life was good. Someone was showing up to flatter him with dogs and a smile. Why would he say no? The dogs were cute. The flattery was nice. The wife got a title. Everyone won.
But the honeymoon lasted barely two years before both sides dropped the pretense entirely.
The reason was straightforward. As we covered before, climate shifts had reduced the Western Regions' three major routes to essentially one viable road: the northern route. Gaochang sat at the toll gate of that northern route, and Gaochang had a consistent policy toward all travelers regardless of origin or purpose:
And this is not just a story. Climate change really did this.
Historical records and modern studies confirm it. Between 420 and 600 CE, the Tarim Basin experienced severe cooling and drying. Water shortages made the oasis routes there nearly impossible to travel. The northern route, the one through Gaochang, became the only reliable path.
Gaochang sat right at the gate of that route. If you wanted to go west, you had to pass through them. And if you wanted to pass through them, you had to pay. Whether you were a merchant doing business or an envoy heading to pay tribute to the Heavenly Khan, you were paying Gaochang first. No exceptions.
The other Western Region states, especially Yanqi, were not happy about this. Yanqi was the most vocal complainer, but other oasis kingdoms like Kucha, Khotan, and Kashgar were also suffering. They eventually brought the complaint directly to Li Shimin: please, Heavenly Khan, reopen the central route through the Western Regions so we do not have to deal with this extortionist.
Li Shimin agreed. The Dunhuang prefect began establishing relay stations along the old Loulan route, in what is now the Lop Nor basin. With imperial backing, merchants could now bypass Gaochang entirely. They could travel directly west from Dunhuang, brave the deep desert route, and arrive safely in Yanqi. The middle artery was officially open for business.
King Qu Wentai retaliated by throwing a spectacular military tantrum. He marched his army into Yanqi, breached their city walls, looted their treasuries, kidnapped their civilian population, and strutted back home like a peacock who just won a fight against a chicken.
Now, Qu Wentai's logic was brutally pragmatic. When someone cuts off your income, that is like killing your parents. And if you kill my parents, I cannot live under the same sky with you, right? It is an old saying, and Qu Wentai took it very seriously.
He could not do anything to the Tang directly. They were too strong. But Yanqi? Yanqi, wash your neck. Let me beat you to the ground.
After the raid on Yanqi, Qu Wentai decided to stop pretending that he respected Tang authority.
First, he formed a military coalition with the Western Turks and hit Yanqi a second time. Three cities fell. Valuables were looted. The population was abducted.
Second, he started detaining tribute envoys from other Western Region states who happened to be passing through Gaochang. Because nothing says "I am a reasonable ruler" like kidnapping diplomats.
And third, he wrote a personal letter to the Xueyantuo Khan:
"Your position as Khan is the equal of Li Shimin's. Why are you acting like his dog? Have some self-respect."
When Li Shimin's envoys arrived to demand an explanation, Qu Wentai's response was genuinely remarkable.
"Eagles have their sky. Chickens have their grass. Cats have their corners. Mice have their holes. Why exactly is this your business? Does managing everyone make you feel important?"
Translation: "Mind your own business, you busybody."
Li Shimin's reply to this was three characters: "jun shan zi tu." You should think carefully about your own situation.
Translation: "I gave you a chance. You just blew it."
Then came the final exchange.
Li Shimin: "Come to Chang'an in person, make a formal apology, and everything before this gets erased."
Qu Wentai: "I am suffering from hemorrhoids and cannot ride. Next time."
Yes. Hemorrhoids. That was his excuse. The king of Gaochang, ruler of a kingdom that sat on the Silk Road's golden goose, told the Emperor of the Tang that he could not travel because his butt hurt.
This is either the most brilliant diplomatic move in history or the dumbest. I will let you decide.
Spoiler alert: it was the dumbest.
Li Shimin's patience was completely exhausted.
In 639 CE, Hou Junji was appointed Grand Commander of the Jiahe Road expeditionary force, with Xue Wanjun and Xue Guer as deputies. The Tang marched on Gaochang.
Qu Wentai had done his calculations and felt comfortable:
"If you bring more than thirty thousand troops, you cannot supply them across that desert. If you bring fewer than thirty thousand troops, I will eat you alive."
Hou Junji: "Twenty thousand cavalry. Come and try."
Qu Wentai: "I will, actually. I will —"
"Terrified and with no options remaining, he fell ill and died."]
Inside Ganlu Hall, Hou Junji's heart was beating a little faster than usual.
He was making a serious effort to stay composed. His eyes swept across the hall once, then again. Nothing. Not a single reaction he wanted to see.
Why was nobody looking at me with admiration?
The old veterans like Qin Shubao and Li Jing were one thing. Those men had seen every kind of achievement under heaven. But Su Dingfang? He was still a relative newcomer. Why was he standing there as if Hou Junji did not exist?
Was frightening an enemy king to death no longer considered an accomplishment? Had standards in this hall become that unreasonable?
In the end, it was Li Shimin who took pity on him. The emperor looked over and gave a brief nod.
"Not bad."
Two simple characters.
Hou Junji immediately felt much better.
Yes. That is it. That is the recognition I deserve.
Li Shimin, meanwhile, was actually somewhat annoyed.
"People like this have no sense of proportion. Always eager to act tough, then crumbling the moment real pressure arrives."
"To die so easily was almost a kindness he did not deserve."
Fang Xuanling and Du Ruhui exchanged a look. A king dying from fear before the battle even began, then having the story preserved in the official histories for future generations to laugh at for a thousand years. Calling that a kindness was, by any standard, a generous interpretation.
As for the larger strategic situation, Li Shimin viewed it quite differently. The Tuyuhun question was troublesome because Tibet sat nearby, waiting to become a factor. Gaochang had no such complications. In his eyes, the matter was simple. Gaochang needed to disappear.
His tribute envoys had been detained. In the Western Regions. By Gaochang. The sheer audacity of it still irritated him. Apparently Qu Wentai believed distance from Chang'an came with diplomatic immunity.
Li Shimin was not the sort of ruler who enjoyed sitting on his anger. The order came immediately.
"I care about none of the other details of this campaign. Qu Wentai must be captured alive and brought to Chang'an."
"He has spent years ruling the Western Regions. I am sure he has mastered the local dances."
"He should make an excellent dance partner for Illig Qaghan at the next imperial banquet."
Hou Junji's back straightened noticeably. The praise felt good. The image felt even better.
Unfortunately, the conversation quickly moved in a different direction. Li Shimin showed no interest in discussing Hou Junji's future conquest of Gaochang. Instead, he focused on something far more practical.
"This desert route. Can it be fully opened and maintained?"
Li Shimin kept a remarkably precise account of the empire's finances in his head. The tolls Gaochang collected from passing merchants were, from his perspective, simply money that ought to have reached Tang territory instead. If Gaochang could not be removed immediately, then the bypass route had to function permanently. The amount involved might seem insignificant compared to the empire's total revenue. Li Shimin disagreed. Money left on the table was still money left on the table.
Having spent months operating around Lüfu County and the Hexi Corridor, Hou Junji knew the terrain better than most people in the hall. He considered the question briefly. Then he nodded.
"It can be done."
"Good." Li Shimin accepted the answer without hesitation. "Then I leave the matter to you, Junji."
The assignment was delivered as casually as if he were discussing tomorrow's weather. Seeing the satisfaction immediately appear on Hou Junji's face, the emperor decided that was enough encouragement for one day. He pointed toward the light screen.
"Continue watching."
[Lightscreen]
[To be fair, Qu Wentai's confidence was not entirely baseless.
The route from Dunhuang to Gaochang was one of the harshest military corridors in the Western Regions. Anyone who looked at a map could understand why Gaochang's rulers had always believed geography was their greatest ally.
The Tang poet Cen Shen, who later served in the Anxi Protectorate, left behind a vivid description of travel through the region:
"For ten days we crossed the gravel wastes, where the winds never cease.
*The horses trod upon shattered stone, and blood flowed from all four hooves." *
The image is dramatic, but it also reveals a practical military problem. The Tang cavalry of this period did not widely employ iron horseshoes in the way most people imagine. At first glance, that seems strange. Archaeological evidence shows that various forms of hoof protection already existed in northern China centuries earlier. Given the Tang Dynasty's reputation as one of the most militarized states in Chinese history, many historians have wondered why horseshoes never became standard equipment.
The answer lies in the nature of Tang warfare.
Heavy cavalry and horseshoes tend to develop together. The more armor placed on a horse, the greater the strain on its hooves. Once a mount is carrying an armored rider, additional equipment, and sometimes armor of its own, hoof deterioration becomes a serious concern. Under those conditions, iron shoes are no longer a convenience. They become a necessity.
The Tang military, however, built much of its strength around highly mobile cavalry forces. Their horses carried lighter loads and were expected to cover enormous distances at speed. Hoof wear certainly existed, but not at a level severe enough to force empire-wide standardization.
There were also practical difficulties.
Forging the iron plates themselves was not particularly challenging. Producing large quantities of specialized horseshoe nails was another matter entirely. The nails had to be strong enough to endure long campaigns while remaining precise enough not to damage the hoof. That required a level of metallurgical consistency that was not always easy to achieve.
More importantly, hoof protection in the ancient world was rarely standardized. Different climates and terrain often required different solutions. Iron shoes worked well in some regions. Leather coverings were preferred in others. Wooden attachments could be useful in muddy ground, while thick hide wrappings offered protection against thorn-covered terrain. Maintaining all of these options across a vast military logistics network was an administrative headache few commanders were eager to embrace.
Had the Tang already solved those problems and fully standardized horseshoes throughout its cavalry forces, Qu Wentai might have shown considerably more caution before provoking them.
Unfortunately for him, horseshoe technology turned out to be irrelevant.
Hou Junji simply drove his cavalry forward at a relentless pace and reached the desert frontier far sooner than Gaochang expected. By the time news of the Tang army's advance reached the royal court, Qu Wentai suddenly discovered that all of his carefully prepared calculations looked much less convincing than they had a few months earlier.
The shock proved too much for him.
Before the Tang army even reached Gaochang, the king fell seriously ill and died.
When the news spread through the expeditionary army, several vanguard commanders immediately proposed launching a surprise attack. Gaochang's leadership had been thrown into chaos, morale was collapsing, and opportunities like this rarely appeared twice.
Hou Junji refused.
His reasoning was straightforward. From his perspective, the purpose of the campaign was not merely to conquer Gaochang. Conquest was the easy part. The real objective was punishment.
Gaochang had rejected imperial authority, detained Tang envoys, and repeatedly ignored warnings from Chang'an. The kingdom had forced the Son of Heaven to dispatch an army in person. If punishment was the purpose, then the Tang army had no need to behave like thieves taking advantage of confusion.
As the old saying went, a righteous army does not strike a state in mourning.
Whether everyone agreed with that interpretation was another matter entirely.
Under Hou Junji's orders, the Tang army advanced in perfect formation. Banners flew high above the columns, drums sounded in slow rhythm, and the entire force marched forward with all the ceremony appropriate for paying respects to a recently deceased ruler.
From a modern perspective, however, the scene creates a somewhat different impression.
One cannot help feeling that Gaochang's citizens were being presented with a very specific message. Yes, the Tang had come to acknowledge the king's passing. They had simply chosen to bring twenty thousand cavalry along for the occasion.
The campaign itself unfolded with remarkable speed.
The fortress of Tiandi fell after only half a day of fighting, producing more than seven thousand prisoners. By the following day, Tang forces had already reached Gaochang's capital and established siege lines around the city.
The newly enthroned Qu Zhisheng examined the situation carefully. On one side stood the capital. On the other stood the army that had somehow crossed the desert, captured a major fortress almost immediately, and arrived at the city gates before the kingdom had even finished mourning the previous king.
After considering these facts, Qu Zhisheng made what historians generally regard as a very reasonable decision.
He surrendered.
The entire city was handed over without significant resistance.
Hou Junji then divided his forces and moved methodically across the kingdom. One city after another submitted to Tang authority. By the time operations concluded, twenty-two cities had been secured, eight thousand households registered, and more than twenty thousand captives taken under imperial control.
The collapse happened so quickly that local people eventually composed a nursery rhyme about it:
"Gaochang's army is winter frost.
The Han army is the blazing sun.
*When sunlight falls upon the frost, *
*Nothing remains." *
The Kingdom of Gaochang had survived through nine generations of rulers. Its dynastic lineage lasted exactly 134 years. It was now permanently erased from the map.
Overriding the fierce objections of his civilian ministers, Li Shimin formally annexed the territory, establishing the Prefecture of Xizhou.
The Great Tang finally possessed a heavily fortified bridgehead in the Western Regions. The imperial war machine began sharpening its blades. The Western Turks were next on the menu.]
Inside the Chengdu administration hall, everyone's attention quickly shifted to a completely different matter.
"Another kingdom down," Zhuge Liang noted. His tone was flat, purely analytical. His eyes, however, gleamed with calculation. "Still, compared to Gaochang, I find this iron horseshoe business far more interesting."
He tapped the armrest lightly. "A small amount of iron, wood, or leather in exchange for healthier horses and longer service life. The cost is negligible compared to the return. Very cost-effective."
He shook his head with the satisfied air of someone who had just found money in a coat pocket.
"Another useful tool added to the collection."
Zhao Yun had seen similar things before. After organizing his thoughts, he spoke up.
"When I was in Liaodong, I saw some Hu tribesmen attach wooden pieces to their horses' hooves using rope and nails."
He paused briefly before shaking his head.
"At the time, it seemed like a minor trick. I never imagined it could have such far-reaching effects."
Zhang Fei, meanwhile, was still eagerly waiting for the first batch of warhorses from Yongzhou and Liangzhou. Anything related to cavalry immediately caught his interest.
"If people already knew about it," he asked, "why was it not taken more seriously?"
Liu Bei looked at the enormous map of Tang territory displayed on the light screen and could not help sighing.
"What other reason could there be?" A wry smile appeared on his face. "The Hexi Corridor. The Hetao Basin. Endless grasslands and endless horses. When horses are everywhere, few people think about how to extend the life of each one."
The hall fell quiet for a moment. Zhang Fei's expression grew noticeably complicated. Some people worried about not having enough horses. Others worried about using too many horses. The difference was enough to make a person jealous.
Zhao Yun, however, was already thinking several steps ahead. If every warhorse under his command received iron horseshoes, their endurance would increase dramatically. Long-distance marches would become easier. Rough terrain would no longer wear down their hooves so quickly. Stronger hooves also meant heavier loads, which meant better armor, which meant stronger cavalry. The heavy cavalry formations shown in previous broadcasts no longer seemed like distant fantasies.
The more Zhao Yun calculated, the more attractive the idea became. Without hesitation, he turned toward Zhang Fei.
"Yide."
The moment he heard that tone, Zhang Fei felt his heart sink. He knew that voice. Whenever Zhao Yun addressed him with that much politeness and sincerity, it usually meant Zilong had set his sights on something important. And unfortunately, that something often belonged to him.
Sure enough, Zhao Yun got straight to the point.
"When the first cavalry contingent arrives from Yongzhou and Liangzhou..." He looked directly at Zhang Fei. "Can I take command of it?"
Zhang Fei nearly groaned. I knew it.
He immediately put on the expression of a man contemplating great matters of history, then raised a finger toward the light screen.
"Elder Brother." His tone became extremely serious. "Did you hear that part just now?"
Liu Bei blinked. "Hear what?"
Zhang Fei nodded solemnly. "Gaochang survived for more than a hundred and thirty years. A truly remarkable achievement."
He looked completely sincere.
"As a matter of historical significance, I think we should discuss that first."