Tang Dynasty China Conquers Constantinople (7th Century - 10th Century)

[Teriyaki]

One of my favorite pieces of Tang Dynasty sculpture and art


The Tang Dynasty is considered by most Chinese historians to be one of China’s golden ages. From the 7th Century to the 10th Century, art and culture flourished, in no small part thanks to the Emperors who sat on the throne, including China’s only female Emperor, Wu Zeitan. During this time, the Tang Dynasty reopened the Silk Road, initially in 639, then again in 699 under Empress Wu’s reign when the Silk Road was recaptured from Tibetan Forces. Through this road, connections were made between the West and the Far East, and ideas were exchanged along the road.

What if the Tang Dynasty rulers saw the reestablishment of the Silk Road as a way to extend their territories and empire beyond China and into Eastern Europe? During the time of the Tang Dynasty, Europe was in the grip of what is known to historians as the Dark Ages. While China was flourishing, Europe was reeling from the fall of Rome that occurred in 410. The Roman Church split in two, resulting in the Western and Eastern Roman Empires. If China had the ambition to look westward towards Constantinople and the Byzantine Empire, it seems that China would have been able to conquer them easily. I am interested to see what people think would have happened had Constantinople had fallen to Tang Dynasty forces and if the push would have ended there, or the push would have been able to continue further into the Western Roman Empire.

 

[XFE]

*reads*

*re-reads*

Ever heard of logistics? Or the behemoth standing in the way known as the Abbasids?

 

[Teriyaki]

*reads*

*re-reads*

Ever heard of logistics? Or the behemoth standing in the way known as the Abbasids?

Educate me as to what you mean. I am willing to learn, but please don't be a smart alec about it.

 

[Monter]

Educate me as to what you mean. I am willing to learn, but please don't be a smart alec about it.

There are 6,800km (4,200 miles) between Chang'an and Constantinople on a straight line, for a non-nomadic bureacratic military like the Tang to supply an army all that way is completely impossible, particularly with the Arab caliphates on the way (you know, the Caliphate that beat the Tang at Talas). Also your claims that "Europe was in the grip of what is known to historians as the Dark Ages" and "The Roman Church split in two, resulting in the Western and Eastern Roman Empires" are both false.
1. Historians have discarted the "dark ages" narrative decades ago, even so the feudalism characteristic of the dark ages wasn't present on the Byzantine Empire.
2. The Great Schism happened in 1054, a century and a half after the fall of the Tang.
So you somehow need the Tang to, somehow, crush the Caliphate, keep the Tibetans and Gokturks in check to not lose Gansu as in OTL, keep marching a huge army across Asia, then you have two routes: through the Middle East or through the Pontic Steppe, as far as I know the Tang didn't have a navy in the Mediterranean so the ME route leads to a dead end in Anatolia, so your 100,000 strong Tang army has to walk all the way through a nomadic heartland, any supply somehow coming from Kucha is getting harrased by Pechenegs, Khazars, Magyars, Cumans, depending on the period and then you enter Bulgaria, pass through it and reach Constantinople... then what? without a naval presence in Marmara your great besieging army can't do much (the Persians learned it in 626 and the Arabs tried to contest it, unsucessfully), so unless the Tang also develop a blue-water navy and perform the Cape crossing centuries earlier you meet another dead end, whoever is the Emperor at the time probably got murdered before the army even reached the Caspian because this whole endeavor is hopeless anyway.

 

[XFE]

Educate me as to what you mean. I am willing to learn, but please don't be a smart alec about it.

The Tang would have trouble conquering and holding Western Central Asia, let alone Constantinople.

Chinese armies, including Tang armies were not nomadic horse armies that lived off the land, but were large, infantry-based sedentary armies that relied on supply lines stretching all the way back to the Tang heartland in Guanzhong. Men, material, and orders had to travel thousands of miles over weeks to reach the frontline, meaning that Tang campaigns in central asia were already immensely costly--even later campaigns a millennia later in the Qing-Dzungar Wars in Xinjiang no less ended up as definitively unprofitable ventures.

OTL has given us ample proof that the Tang was overstretched, and could not hold onto her conquests in the long term. When the Abbasids looked north into Central Asia, the Tang simply had no counter. And where's the incentive or necessity of throwing a counterpunch against the Caliphate? The Tang state's economic and geopolitical interests remained firmly in the East, and her defeat at Talas against the Abbasids would never have posed a threat to Tang stability. Control of the Western regions was simply inconsequential. Even though Tang military strength rebounded extraordinary quickly after Talas, there was still neither the will, the incentive nor the means for the Tang to pursue an aggressive policy of Westwards expansion.

 

[Tanc49]

Constantinople was not takable until a few centuries later IMHO. At the time it wasn't actually that weak...

 

[RogueTraderEnthusiast]

As much as the idea is fascinating (and it really is) the distance is incredible. This would truly be "World Empire" status power here.

First you'd need to address the security of the Hexi Corridor, at the very least. This might mean some sort of persistent relationship between China and the Steppe, be it like the Xiongnu, or something altogether different, further, the same between China and Tibet. Otherwise that corridor snaps everything in two rapidly, which could be a disaster.

However, if we set a precondition of a Tibetan conquest, and negotiated relationships with the Steppe, we could have something here. Since a lot of the personal loyalties of new steppe leaders relied on personal success, China could effectively supply and endorse them riding westward WITHIN China, to then raid Central Asia. That is one difficult treaty to maintain, with details to resolve, but lets also patch that issue.

We now have a China with relatively secure logistics, but not always as the scale required, which means the Tarim Basin needs to be able to support any army, or the Chinese will be establishing huge food stores that then need to be guarded. Which is getting expensive.

Further, we then take Central Asia - it's demographic core in the Fergana valley being the focus. This means we now have two regions highly exposed to the steppe, which still needs some sort of resolution.

Then the Abbasids. Perhaps your resolution is to effectively ceremonialise the inheritance of power with the steppe groups to the extent that their leadership challenges happen on the edge of Central Asia and the Abbasids, in which case you've got the far west of the Chinese Empire effectively 100% at war with the Abbasids at all time. Ignoring that this then means perpetual war with a significant trade partner, even if indirect trade, a counter-attack is easier for the Abbasids than the Chinese.

So you need to figure out a way to secure Persia. Now this is easier, as once you've conquered Persia, you could settle it en-masse. The Chinese certainly had the demographic advantages there, but your logistics are still perilous by land or sea (because well, India and Indonesia can dip their fingers in this pie.)

However, if the Chinese can somehow maintain their Western Protectorate in Persia, then that can be the base of operations for a truly collossal endeavour.

The final point of this is that to perform the challenge you want, you have to address multiple sets of major geopolitical challenges. Not impossible, but you're basically looking at a China-built Steppe coalition, conquest of Tibet, Conquest of Persia, Conquest of Mesopotamia, THEN Conquest of the Romans. This is Genghis Khan/Caliphate level stuff here. Not to mention the need to never suffer anything like An Lushan.

I don't really see it as plausible, not unless the Tang Dynasty is radically more successful than it already was. If you want the Tang invading Rome, you might need to have them become truly the World Empire, by conquering Indonesia, and potentially even India. At which point the sheer economic power in play, and the resources at hand make the task much easier. Especially since this secures naval logistics. But even then, you have the internal issues to resolve.

 

[Teriyaki]

Thank you very much for explaining it so well RogueTraderEnthusiast. I understand better now the factors and how it would be hard to accomplish such a feat.

 

[The Tai-Pan]

Thank you very much for explaining it so well RogueTraderEnthusiast. I understand better now the factors and how it would be hard to accomplish such a feat.

Logistics kills so many cool ideas.

 

[Teriyaki]

Logistics kills so many cool ideas.

LOL true.

 

[chornedsnorkack]

There are 6,800km (4,200 miles) between Chang'an and Constantinople on a straight line, for a non-nomadic bureacratic military like the Tang

How non-nomadic were the Tang?

to supply an army all that way is completely impossible, particularly with the Arab caliphates on the way (you know, the Caliphate that beat the Tang at Talas).

And is not in the way - because of the Pontic steppe you mention below.

Also your claims that "Europe was in the grip of what is known to historians as the Dark Ages" and "The Roman Church split in two, resulting in the Western and Eastern Roman Empires" are both false.
1. Historians have discarted the "dark ages" narrative decades ago, even so the feudalism characteristic of the dark ages wasn't present on the Byzantine Empire.
2. The Great Schism happened in 1054, a century and a half after the fall of the Tang.
So you somehow need the Tang to, somehow, crush the Caliphate, keep the Tibetans and Gokturks in check

Keeping the Gokturks not merely in check but under control is the key. The only way it is possible at all.

to not lose Gansu as in OTL, keep marching a huge army across Asia, then you have two routes: through the Middle East or through the Pontic Steppe, as far as I know the Tang didn't have a navy in the Mediterranean so the ME route leads to a dead end in Anatolia, so your 100,000 strong Tang army has to walk all the way through a nomadic heartland, any supply somehow coming from Kucha is getting harrased by Pechenegs, Khazars, Magyars, Cumans, depending on the period and then you enter Bulgaria, pass through it and reach Constantinople... then what? without a naval presence in Marmara your great besieging army can't do much (the Persians learned it in 626 and the Arabs tried to contest it, unsucessfully), so unless the Tang also develop a blue-water navy and perform the Cape crossing centuries earlier you meet another dead end,

Um, no.
The Tang simply send a reasonable number of shipwrights behind their nomadic cavalry main force. With assignment to build a navy on Black Sea and then decide the siege of Constantinople.
Bosporus is no wider than Yangtze. And South China was conquered by regimes based on Changan twice - in 589 and 621 or so.

The hard part here is sending the cavalry all the way Changan to Constantinople and seeing to it that they keep obeying and bring the shipwrights along.

It is not impossible.
In 1242, a cavalry force stood on Adriatic. Then they got orders to return... and did go back.
To Karakorum.
Coming from Adriatic, Changan is no further than Karakorum!
And from Odessa, Marmara Sea is closer than Adriatic (and less hills in the way).

The key here is do what the Mongols would do 600 years later OTL, and do it with a regime whose homebase is on the Chinese side of Great Wall.
Ögedei Khan had campaigned as far as Afghanistan in Genghiz Khan´s time - but in his reign, I don´t see mentions of him leaving East Asia again.

What would be necessary for Tang Gaozu to command Göktürk loyalty so as to be able to sit in Changan and send them to Adriatic and Marmara and expect to be obeyed, the way Ögedei could?

 

[Monter]

How non-nomadic were the Tang?

You mean how much their armies were composed of nomads vs sedentary? Most of them were Chinese conscripts operating under supply lines, Anxi surviving after being cut off by the Tibetans is considered quite a feat.

Um, no.
The Tang simply send a reasonable number of shipwrights behind their nomadic cavalry main force. With assignment to build a navy on Black Sea and then decide the siege of Constantinople.
Bosporus is no wider than Yangtze. And South China was conquered by regimes based on Changan twice - in 589 and 621 or so.

Errr, what? Try reading what you're saying, walking away over 6000km in a extremely unreliable conditions, carrying tons of wood, and also your overstretched army now needs quite a number of engineers and shipbuilders, then... what? you just said to ignore the "Caliphate route" instead going to through the steppe, the Bosphorus is irrelevant there, also the Yangtze has several cities with the proper infrastructure to both build dock a fleet (plus the Yangtze isn't a continent away from the center of power of those dynasties), there is none in the Black Sea 600-900 AD outside the Byzantine Empire, what you expect? The Chinese to load all the materials at the beach and build all the ships? Where are they docked? What makes you believe that they are going to defeat the Byzantine fleet? This whole thing makes Hannibal crossing the Alps look like a jog.

It is not impossible.
In 1242, a cavalry force stood on Adriatic. Then they got orders to return... and did go back.
To Karakorum.
Coming from Adriatic, Changan is no further than Karakorum!
And from Odessa, Marmara Sea is closer than Adriatic (and less hills in the way).

Once again, the Mongols were a nomadic empire with little problem with logistics as long as they kept in good supply of grazing land (otherwise we have Ain Jalut), the armies the Tang sent west were traditionally standing armies composed of infantry and mixed unit of heavy and light cavalry, supplied from Chang'an, not the same thing.

 

[Richard V]

Once again, the Mongols were a nomadic empire with little problem with logistics as long as they kept in good supply of grazing land (otherwise we have Ain Jalut), the armies the Tang sent west were traditionally standing armies composed of infantry and mixed unit of heavy and light cavalry, supplied from Chang'an, not the same thing.

They could do a version of Russian expansion, in phases over a century or two.

 

[chornedsnorkack]

Errr, what? Try reading what you're saying, walking away over 6000km in a extremely unreliable conditions, carrying tons of wood,

No. Just the steel carpentry tools.
Wood can be found in Balkan Mountains and Carpathians.

and also your overstretched army now needs quite a number of engineers and shipbuilders, then... what? you just said to ignore the "Caliphate route" instead going to through the steppe, the Bosphorus is irrelevant there, also the Yangtze has several cities with the proper infrastructure to both build dock a fleet (plus the Yangtze isn't a continent away from the center of power of those dynasties), there is none in the Black Sea 600-900 AD outside the Byzantine Empire, what you expect? The Chinese to load all the materials at the beach and build all the ships? Where are they docked?

Lower Danube delta.
Bulgars, in 7th century, did not come at orders of Tang emperors and did not have siege and shipbuilding engineers in tow. Now just imagine that Bulgars do come, but as an army commanded by Tang...

Once again, the Mongols were a nomadic empire with little problem with logistics as long as they kept in good supply of grazing land (otherwise we have Ain Jalut), the armies the Tang sent west were traditionally standing armies composed of infantry and mixed unit of heavy and light cavalry, supplied from Chang'an, not the same thing.

Göktürk, in 6th century, had also ridden west. Not quite as far as Mongols, but they did get as far as Crimea.
Now just think that the Tang, after subduing the eastern Göktürk in 630, are able to send them not just to follow the western Göktürk, but go beyond...

 

[Admiral Fischer]

They could do a version of Russian expansion, in phases over a century or two.

Central Asia isn't some random frozen wasteland.

 

[Admiral Fischer]

Now just think that the Tang, after subduing the eastern Göktürk in 630, are able to send them not just to follow the western Göktürk, but go beyond...

So what persuades the emperor to send an army of engineers and technicians to the lands beyond the desert, let alone entrusting someone with such an army?

 

[Worffan101]

Europe was in the grip of what is known to historians as the Dark Ages. While China was flourishing, Europe was reeling from the fall of Rome that occurred in 410.

The "Dark Ages" did not represent a serious loss of technology except in terms of large-scale urban infrastructure. There was a marked decline in urban populations and re-alignment of power to rural fortified estates, a breakdown in western European trade routes, a massive loss of Italian population due to the Byzantine/Goth wars, but that only really was a serious problem from the 6th century after the plagues ran through until about the 9th or so, when northern and western Europe got their feet under them and started to properly deal with Norse raiders which let them re-establish trade routes with domestic traders,and even then the Med was pretty quick to get back on its feet despite the Byzantines and Sassanids gutting each other.

Military and even agricultural technology, though, continued to advance despite the loss of funding for infrastructure projects and hard sciences.

(you know, the Caliphate that beat the Tang at Talas)

Talas was a strategic draw, the Tang couldn't have done anything with a tactical victory due to the logistics problem you mention, and the Abassids were doomed anyway because the logistics of keeping their multi-ethnic empire together were...less than great.

then you have two routes: through the Middle East or through the Pontic Steppe

Or you can try to push through the Caucasus, if you want a Georgian necktie.

How non-nomadic were the Tang?

Haha, um, about as not-wet as the Sahara is. The Tang, like other Han Chinese dynasties, had their power base in the settled agrarian peoples of the lush North China Plain, and to a lesser extent among the valley peoples of the Yangtze drainage system and southern Chinese coast (ever wonder why Mandarin and Cantonese are so different? Basically all the Chinese south of the North China Plain descends from a different set of branches of Sinitic from the northern variety). The nomads typically lived in the northwest of the plain (in fact, the Great Wall is basically a failed attempt to erect a defense against those peoples) and were generally either rivals of the Han states of north China, conquest dynasties of part or all of China (the Jin even took the plain, then got fucked up by the Mongols, then came back 400 years later after rebranding and took over the whole country), or client governors at times.

The Tang simply send a reasonable number of shipwrights behind their nomadic cavalry main force. With assignment to build a navy on Black Sea and then decide the siege of Constantinople.

You seriously expect them to build with trees from the Romanian coastal regions? Good luck getting ships worthy of the name. Or breaching the Theodosian walls in the face of a functional garrison (it took the Ottomans cannons and facing a devastated city that had suffered plague and famine on top of the ruin of their former empire to get past those walls, and the Ottoman base of operations was in Anatolia plus they had lands on both sides of the Bosporus by this point).

tl;dr the Tang conquering Constantinople is, as people have said upthread, logistically impossible.

 

[Richard V]

Central Asia isn't some random frozen wasteland.

It too was part of the Russian Empire.

 

[BellaGerant]

It too was part of the Russian Empire.

In the 19th century over the course of half a century, after gunpowder weapons had rendered the age of nomadic steppe hordes in the Eurasian steppe a bygone era.

Central Asia's tougher than Siberia since there's more possible threats to settlement and supply lines than Siberia, where the native population was rather sparse, and Siberia has better river systems to allow faster movement East-Westward. Steppe nomads from different regions could very well migrate into the region and wreck havoc on colonisation or wipe out Tang armies so far from their traditional supply routes. The fact that China didn't fully subdue the Eastern Steppe (with all the Mongols, Xiongnu, Khitans, Jurchen/Manchu) until the 18th century under the Manchu Qing dynasty despite so many dynasties and so many centuries doesn't lend much credibility to the idea that the Tang would be able to subdue a steppe region even further away from their heartland than the Eastern Steppe centuries before the Eastern Steppe was pacified OTL. Let alone dealing with the Abbasids or just the fact that there's just no economic incentive for such a massive military campaign with no guarantee of rewards (at least for the years and years it would take to campaign) or political incentive (rather the opposite, since an ambitious general with such a large force operating so far from the capital is a bit of a danger, as was often the case in Chinese history).

 

[Richard V]

In the 19th century over the course of half a century, after gunpowder weapons had rendered the age of nomadic steppe hordes in the Eurasian steppe a bygone era.

Central Asia's tougher than Siberia since there's more possible threats to settlement and supply lines than Siberia, where the native population was rather sparse, and Siberia has better river systems to allow faster movement East-Westward. Steppe nomads from different regions could very well migrate into the region and wreck havoc on colonisation or wipe out Tang armies so far from their traditional supply routes. The fact that China didn't fully subdue the Eastern Steppe (with all the Mongols, Xiongnu, Khitans, Jurchen/Manchu) until the 18th century under the Manchu Qing dynasty despite so many dynasties and so many centuries doesn't lend much credibility to the idea that the Tang would be able to subdue a steppe region even further away from their heartland than the Eastern Steppe centuries before the Eastern Steppe was pacified OTL. Let alone dealing with the Abbasids or just the fact that there's just no economic incentive for such a massive military campaign with no guarantee of rewards (at least for the years and years it would take to campaign) or political incentive (rather the opposite, since an ambitious general with such a large force operating so far from the capital is a bit of a danger, as was often the case in Chinese history).

I’m not saying it’s likely, but it’s not impossible. The fact that it wasn’t done until the 19th century does not prove it cannot be done earlier. In the 7th century the nomads of Central Asia were not the fearsome Mongols. They had not adopted stirrups while the Tang had. They were disunited and led by local aristocrats rather than having meritocratic promotion. They were never known to be good at sieges.

Geographically Central Asia had good waterways for logistical support. Starting from the Anxi Protectorate, one only has to follow the Amu Darya river to Nukus, south of the Arial Sea, make a short overland trip to the Caspian, then follow the Volga to the Don, and you are in the Black Sea. Not at all more difficult than crossing Siberia. Using the Russian example, once the Tang settle Transoxiana they would be on the doorstep of the Khazars.

For a sedentary people like the Chinese or Russians to expand like that it would be a slower process and they would need structural push/pull factors to keep their empire expansion-minded for multiple generations instead of a single generation or two.