Li Shimin let out a long, tired sigh. A realization settled deep into his bones.
War was so much easier than actual governance.
Who knew running an empire involved less charging into battle and more staring at grain shipment reports until your eyes burned?
The Light Screen had just casually mentioned that the ancient Roman Empire split into East and West, eventually ruled by four separate emperors. At first, the concept shocked him. But as a man who actually managed a big empire, he slowly understood the logic.
The administrative burden alone was a nightmare that could make even the toughest general start day drinking.
Using the modern terminology of competing administrative centers, the core issue was obvious. Misaligned capitals bred localized corruption and logistical rot. How does a centralized government convince the wealthy taxpaying farmers in the lush southeast to happily fund a standing army freezing out in the western deserts? It was an administrative puzzle that could keep any ruler awake for three straight nights.
One wrong move meant disaster. One delayed grain shipment and the border troops starve. Then the tax collectors squeeze the peasants too hard to compensate. Next comes boiling public resentment, and suddenly you have a full blown armed rebellion with the slogan "The Yellow Sky rises, the Blue Sky is dead" painted on banners across your provinces. Fun times for everyone.
Looking at the history of the Han and Tang dynasties, a dual capital system like Chang'an and Luoyang seemed barely manageable. But glancing at the chaotic track record of Rome, having four simultaneous emperors looked like a recipe for instant civil war. Why not just hand every general a crown and be done with it?
These geopolitical problems were a bit too distant for immediate action. Li Shimin needed to process his own thoughts, sort out the logistical threads, and then present a polished theory to his cabinet. So he kept his mouth shut and shifted his gaze back to the glowing screen, already mentally filing away notes.
The screen flashed the nickname God Guang again, referring to the infamous Emperor Yang of Sui. Li Shimin did not know whether to laugh or cry. He settled for a bitter sigh.
Throwing the lives of a million people into the meat grinder just to build such a massive waterway was the true definition of a prodigal son. The man had more ambition than sense.
Because of Emperor Yang's obsessive need for huge engineering projects, the Sui Dynasty collapsed into a bloody civil war. Millions died. Even now, his own Tang Dynasty had not fully recovered that lost population. Li Shimin did not even want to imagine the possibilities.
If his current empire possessed the fifty million citizens that Emperor Yang had at his absolute peak, why would he be creeping around the Western Regions so carefully? He would simply march a million armored troops straight to the border and settle the debate permanently. No diplomacy needed. Just a lot of shouting and spears.
Daydreams of limitless armies aside, he shook his head and zeroed in on the screen's brief mention of the Ming Dynasty engineer Pan Jixun.
"This specific method for taming the Yellow River..."
Before Li Shimin could even finish his sentence, he felt a sudden sharp tug on his royal sleeve.
"Your Majesty!" The voice was frantic, breathless, and totally lacking proper court decorum. "Give me exactly three days. I can build a scale model and verify this hydraulic theory. If it genuinely cures the flooding of the Yellow River, I beg you to put me in charge of the project!"
The words tumbled out so fast they nearly tripped over each other. Li Shimin blinked, looked down, and realized his Minister of Works, Yan Lide, was the one clutching his royal robe like a desperate merchant in a bazaar who just saw his last chance at wealth.
Looking at the burning fanatical light in Yan Lide's eyes, Li Shimin realized he had no choice but to nod in agreement. The man would probably camp outside his bedroom door otherwise.
"Okay, Lide. I will wait for your model structure."
"Thank you, Your Majesty!"
After securing the imperial green light, Yan Lide practically skipped back to his desk, humming an off key tune under his breath.
The architect was buzzing with so much joy he looked like he might float away.
Yan Lide could already see the royal historians adding at least two extra glorious pages to his official biography. Getting your name carved into the annals of history and having the people build shrines in your honor was the ultimate goal for any official. Curing the Yellow River was a shortcut to permanent godhood.
Of course, calling river management simple was only true if you compared it to the suicidal insanity of leading a cavalry charge deep into the Gobi Desert like the legendary General Huo Qubing. If taming the river was actually simple, the Yellow River would not have spent the last thousand years drowning entire provinces on a whim just to be annoying.
Yan Lide was a master of grand architecture. Therefore, he understood the brutal reality of hydro engineering perfectly well.
The biggest nightmare of the Yellow River was its chaotic winding channels. Clearing out thick sediment from the treacherous bottleneck curves was a logistical nightmare. But right now, this Light Screen had just handed them the solution on a silver platter.
Constrict the water to scour the sand.
It was brilliant. Yan Lide felt that if he failed to seize this golden opportunity, heaven itself would strike him down right there for his incompetence.
The Minister was thrilled. The Emperor was satisfied. The sovereign and his subject exchanged a warm knowing smile. The atmosphere inside the pavilion was absolutely perfect.
As for the screen's cryptic mention of a million canal workers relying on the water route for food and clothing, Li Shimin chose to ignore it for now.
Just looking at the phrase, he could smell a festering bureaucratic rot from a mile away. That kind of localized economic dependency definitely explained why the future Ming Dynasty committed the idiotic act of abandoning ocean shipping entirely just to save jobs. The specific morbid details of that future administrative disaster would likely be revealed later anyway. He could panic about it then.
The Light Screen shifted its focus, bringing up a new set of diagrams and maps.
[Lightscreen]
[First things first, we need to establish a core historical concept. Ever since the Western Zhou Dynasty, the Chinese urban planning system has been incredibly mature and deliberately structured. We do not do random chaos when it comes to building cities. We have rules.
The perfect negative example of this is ancient Rome. The city of Rome was a classic chaotic natural cluster settlement. It had zero central planning. The original geographic layout was completely incapable of handling their later needs. They basically built themselves into a corner.
By the time their population exploded, Roman engineers looked around and realized they were trapped in a chaotic nightmare of rocky terrain. With their current technological level, digging underground tunnels through solid stone was totally impossible. Therefore, building above ground aqueducts that were highly visible was not a display of superior engineering. It was a desperate forced compromise. They had literally no other choice.
Meanwhile, during that exact same timeframe, our Qin and Han Dynasty ancestors were already bored with planning single mega cities. They started designing highly integrated metropolitan urban clusters. Why build one big messy city when you can build a whole system of organized ones?
Let us look at Han Dynasty Chang'an as the prime example. After the empire finally united, the population skyrocketed, threatening to crush the infrastructure under its own weight. The imperial government stepped in immediately. Instead of just letting the city bloat into a disease ridden mess, they systematically relocated specific industrial and logistical functions outward into dedicated satellite towns.
At its peak, the Chang'an metropolitan zone commanded a staggering fifty seven satellite cities. Every single town had a highly specific job, wrapping around the capital like a well oiled machine. No overlap. No waste.
Take Zheng County and Xiayang. The government established dedicated Iron Bureaus there, government run smelting facilities. They concentrated all smelting and metalwork in one spot. It was basically the ancient blueprint for a modern heavy industrial zone.
Then you have places like Yueyang and Hui County. Positioned right on the river, they handled nothing but maritime shipping and canal logistics. They housed transit granaries to feed the surrounding urban sprawl. Lianshao County hosted the Salt Bureau, holding the monopoly on supplying salt to the capital zone.
And my personal favorite is the Ship Master Bureau, a government department dedicated to shipbuilding. They literally picked an empty plot of dirt, threw up an entire new city strictly for shipbuilding, and named the town after the department itself. Pure raw functional zoning. No frills. No nonsense.
Naturally, with this level of advanced urban planning, their water management systems were equally calculated. Everyone knows the famous ones like the Lingqu Canal or the Zhengguo Canal. Here is something interesting. These hydraulic projects were primarily designed to provide daily drinking and municipal water to civilian populations. The whole irrigating the endless farm fields angle? That was actually just a secondary side benefit. A very nice bonus.
The crown jewel of this era is the Longshou Canal. It stretches for seventy kilometers. And it sits thirty meters entirely underground. Yes, you heard that right. Underground.
This monster was built during the reign of Emperor Wu of Han. It took nearly ten years and required the brutal labor of over ten thousand workers. They successfully dragged the waters of the Luo River directly into Chang'an, creating the very first subterranean aqueduct in Chinese history.
If you put the Longshou underground canal right next to a Roman above ground aqueduct, the difficulty scaling becomes incredibly obvious. After all, the vast majority of Roman aqueducts only ran for a dozen kilometers. Even if you string them all together and count the occasional tunnel, finding a single continuous Roman aqueduct that breaks the hundred kilometer mark is extremely rare.
But the Longshou Canal ran for seventy kilometers completely blind, deep in the earth. Anyone who knows basic engineering understands the nightmare of subterranean construction. Digging an underground river requires calculating precise elevation drops without modern lasers, plotting an invisible route, sourcing the perfect water table, conducting raw geological surveys, and managing internal fluid dynamics so the pressure does not blow out the walls.
The technical mastery required for these two projects is not even comparable. It is like comparing a homemade kite to a warship.
This specific subterranean channeling tech is known today as the well canal system, an ancient method of digging underground water channels. After the Han Dynasty conquered the Western Regions, this technology rapidly spread deep into Central Asia.
The locals loved it so much they kept using it for the next two thousand years. You probably know it by its modern folk name, the Karez well system, a type of underground irrigation still used in Central Asia today. It is literally required reading in middle school history textbooks.
Furthermore, post Han Dynasty, the technology for everyday civilian water access never stopped evolving. Modern period piece TV shows love to depict ancient Chinese peasants endlessly cranking wooden buckets up from deep dirty wells regardless of the dynasty. That is a lazy stereotype. And also very boring.
Take the manual water pressure pump. A lot of people think this is a shiny twentieth century invention. In reality, wealthy households in the Song Dynasty were already using mechanical pressure pumps in their backyards. Fancy, right?
Some hardcore historians even argue this simple effective pump design traces all the way back to the Han Dynasty. We just lack the concrete archaeological digs to prove it right now. We just have to wait for someone to dig up a Han Dynasty water pump in the future. Fingers crossed.
This obsession with water engineering bleeds into every single aspect of Chinese civilization. Let us look at the Great Wall. Most people think it is just a giant military barricade. Wrong. So wrong.
A rammed earth wall has one fatal weakness. If it gets soaked in standing water, it melts into mud and collapses. The ancient builders spent an insane amount of time obsessing over drainage. The watchtowers and the curtain walls were built at deliberately staggered heights. They carved intricate drainage gutters right next to the anti cavalry trenches. These gutters fed directly into hidden culverts that safely expelled the rainwater down the slopes. Both the gutters and the culverts had automatic anti clogging designs built directly into the stonework.
This hidden plumbing is exactly why the Great Wall is still standing today. Hundreds and even thousands of years after it lost its military value, the secondary drainage system is still working perfectly. That alone proves the raw technical brilliance behind the blueprint.
Honestly, the technical skill behind the Roman aqueducts does not even come close to the real secret weapon of Roman architecture. The primitive concrete. That was the true marvel of the ancient Mediterranean.
The Italian peninsula is packed with volcanoes. The Romans realized that if you took all that abundant volcanic ash, mixed it with slaked lime and clay, and let it cure, the resulting rock was incredibly hard. This allowed them to build domes and gorgeous arches. Very fancy stuff.
Ancient China really could not compete with this specific trick. Our closest source of volcanic ash is all the way down on Hainan Island. The transportation costs alone would bankrupt the imperial treasury. Sure, we had a makeshift substitute that used iron slag instead of volcanic ash. But let us be honest, the binding strength was heavily compromised. It just was not as good as the real volcanic stuff. Or so everyone thought back then.]
The Light Screen cycled through a series of stunning photographs in high definition.
In another timeline, Liu Bei stared intensely at the towering impossible heights of a Roman aqueduct archway spanning across a lush green valley.
His immediate instinctual reaction was pure disbelief. How could the narrator possibly claim that such a majestic towering structure lacked engineering skill? It looked like a bridge built by actual immortals.
But as the narrator's voice twisted and turned, dismantling the Roman myth and dropping the true secret of their construction, Liu Bei's emotions went on a wild rollercoaster ride.
Just looking at the pristine ruins of those Roman monuments told him everything he needed to know about the tactical value of this primitive concrete. The military applications alone made Liu Bei's hands itch with greed. Fortress walls that could be poured into wooden molds instead of carved from stone block by block. Watchtowers that could cure into solid rock overnight. It was the ultimate defensive advantage. A dream come true.
He was already doing the mental math, seriously considering whether he should draft a slightly illegal diplomatic letter to Shi Xie. He was fully prepared to trade a fortune in premium Han iron weapons just to import crates of this magical Hainan volcanic ash. No cost was too high.
But then the narrator dropped the final casual sentence like a bomb.
A downgraded version replacing volcanic ash with iron slag.
Liu Bei practically vibrated out of his seat. His eyes went wide as saucers. He entered a state of absolute ecstasy.
Iron slag? We have that! We have literal mountains of that useless garbage just sitting outside the blacksmith foundries taking up space! And we have lots and lots of it! We have been throwing it away for years!
The structural integrity might be slightly weaker than Roman ash, but for a guy desperate to fortify his borders against the armies of Cao Cao, cheap unlimited iron slag concrete was not just good enough. It was a total game changer. The heavens had just handed him a miracle.
He turned to Kongming, who was already scribbling notes so fast his brush was a blur, his eyes shining with the exact same realization.
"Kongming," Liu Bei said, his voice shaking with excitement. "Tell the foundries to stop throwing away the slag immediately. We are going to build a wall that even the heavens cannot break!"