What factors led to China re-unifying multiple times throughout history while "Europe" failed to do so after Charlemagne?

Feb 2011
Why'd the Han descendants get treated well?

Also, by aristocracy, Yes, I meant the nobility. They wouldn't have to be related to any Chinese emperor, but they could be. I'm thinking in a European context where dukes, lords, et cetera pass on their titles.
I guess it depends on the character of the person who forced the previous emperor to abdicate, combined with how much a threat the previous bloodline was seen to be.

Chinese officials (excluding maybe imperial relatives) don't pass on their titles. They might use their titles to press their relatives into power, but it's something they have to press. It's not something that's passed on automatically. They have to be careful about it too. Because if they recommended somebody bad, it look bad on them. If an official committed a crime, then the one who recommended them could also be punished. Afterwards appointment by recommendation was gradually replaced with a Civil Service Exam system. Anyway in short the rulers of Chinese provinces tend to be assigned, not inherited.
Likes: Futurist
Aug 2014
The Franks never practiced primageniture. When Charlemagne died, his possessions and authority were passed intact to his son because there was only one heir. But when Louis died, the empire was divided up among the heirs instead of being passed intact to the firstborn. On top of that, there was a civil war as the brothers fought to gain more share of their siblings' possessions. The same things happened in China when there wasn't a clear line of succession, or the obvious candidate was incapable of holding things together.
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Likes: Futurist
Feb 2018
It's definitely a fascinating question. I've never found real scholarly treatment of it, though that's probably because it requires too much diverse knowledge. The only quasi-treatment of this I've seen is by David Graff, who only looks at a specific point in time 600~ CE). He summarizes the scale of it here:

"East Asia followed a different trajectory. The failure of the legitimist Eastern Jin dynasty and its successor states in the south to muster the necessary resources and political will to recover the lost north would at first appear to parallel the Eastern Roman experience, but from there the pattern diverged dramatically. By the early 380s, the (temporarily) dominant warlord in the north was attempting (unsuccessfully) to conquer the south, an effort that would be repeated by the Toba Wei rulers who united the north under their control in the middle of the fifth century. Although they, too, were unsuccessful, their period of dominance in the north saw the beginning of the emergence of a new, mixed-blood elite that combined the martial prowess of the steppe warrior with Han Chinese traditions of literacy and statecraft. When rebellion and civil war split the Northern Wei into two rival regimes in the 530s, Western Wei (later Northern Zhou) in the Wei River valley around the old Han capital of Chang’an and eastern Wei (later Northern Qi) in the North China Plain, the leaders of the western regime pioneered the creation of new military institutions that enabled them to augment their initially meager resources by drawing soldiers from the indigenous (mainly Han) farming population. With the new armies thus created, the Northern Zhou was able to overcome its eastern competitor and reunify the northern part of China in the late 570s. Then, after a coup d’état within the ruling circle had brought a new family to power with the new dynastic name of Sui, the now united north finally succeeded in conquering the south in a massive campaign undertaken in 588–589. Virtually all of the territories once ruled by the Han dynasty were now reunited under a single monarch, but he came from the barbarian north rather than the legitimist south. In Western terms, it was as if Charlemagne had not simply been crowned emperor at Rome in 800, but had gone on to take Greece, Syria, Egypt, North Africa, and Constantinople itself, eliminating the eastern emperor and reconstructing the old Roman Empire—in its entirety—under Frankish rule."

The Byzantines under Justinian realistically had the best chance of reuniting the Roman empire. The timeline of Justinian's conquests roughly matches up with the various successful Chinese dynasties. The Byzantines had a strong base of military institutions to draw from, a truly exceptional general, an expansionist and high-energy emperor who started young, and a solid resource base. It is remarkably similar to the Tang in certain ways (who reunited China about a century later): both had an Emperor of rare ability, a truly exceptional general, and a powerful enemy outside of its traditional territory (Gokturks for the Tang, Sassanids for the Byzantines) that diverted resources and troops. There were of course differences. Li Shimin, unlike Justinian, was a skilled general himself. However, he had to mount a coup to assert control of the dynasty. Relative to their opponents, the Byzantines had greater starting resources than the Tang did, who started in one of the less rich areas of central China and bordered an incredibly fearsome Turkic empire. Yet if we look at the timeline:

1. Eastern Persian campaign 530-1
2. Nika Riots 531 (not a conquest but a distraction)
3. North Africa Prep and Invasion 532-534
4. Sicily/Italy Prep and Invasion 535-540
5. Dalmatia 535-536
6. Southern Spain 552-555

This about matches up with the timelines in the Tang and Song unification wars, where they quickly beat various warlords controlling certain swathes of China, usually taking 1-2 years at most per region, often less. For example, the Song conquered the Shu kingdom in Sichuan, a very inaccessible region, in just one winter campaign with 60,000 troops.

None of these conquests were particularly arduous, and a reunification of the Roman Empire seemed quite feasible in Belisarius and Justinian's lifetime, especially since Justinian had other skilled generals available. However, the so-called Justinian plague seems to have ruined their momentum and caused enormous, compounding problems across the empire. Instead of Italy being pacified and the Byzantines moving onto a new conquest like they did after the Vandal War, they lose control of Italy and have to reconquer it only after they begin to recover their resources from the plague. This wastes over a decade of precious time of Justinian and Belisarius's lifespans.
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Feb 2011
In Western terms, it was as if Charlemagne had not simply been crowned emperor at Rome in 800, but had gone on to take Greece, Syria, Egypt, North Africa, and Constantinople itself, eliminating the eastern emperor and reconstructing the old Roman Empire—in its entirety—under Frankish rule."
I would say the rise of the Sui was more akin to if a Roman of the Western Roman Empire forced his 'barbarian ruler' to yield the throne, and then proceeded to conquer the Eastern Roman Empire as well. Because Charlemagne was a Frank. Yang Jian was a Han.
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Sep 2016
That doesn't say that much as it's less the number of languages in itself, but the ratio between languages: if out of (say) 29 languages in China, two of them are spoken by 70% of the population gives a totally different dinamics than the variant of were five-six languages that are spoken by 70% of the population.

It's one of the main reasons Europe couldn't "unite": You had had multiple "big" languages that were quite far one from another (French, English, German, Russian). Big enough to have a say, but too small to become a "hegemon", and too far to become "coagulation poin" (latin-germanic-slav ... more or less nothing in common).
Modern Mandarin domination is... well, modern. Sichuan used to have its own language, while the rest of the south used to speak languages that weren't even Sinic to begin with. Also in the north over centuries you had various ethnic grouos, where Shatuo, Xiongnu, Di, and others who didn't speak Chinese natively. Neither of this was a problem, to the contrary, even leaders of those ethnic groups had ambitions to unite the China, like Charlemagne wanted to with Rome.

Languages were never a significant issue, because the only language of importance, was the lingua franca and the language of the administration: Latin for Europe, Classical Chinese for China.
Mar 2012
The reason in Europe is because the political system of titles and lands promoted division. While the Persian and Roman Empires divides lands by provinces which are owned by the state, and those who served them are serving the state, in Europe if you had a title (King of X, Duke of Y), you might be vassal to someone, but you own the land and pass that title down.

So, Charlemagne for example came from the Franks. Their succession laws stated that he should give titles to his sons, and so he created titles and split his Empire. Kingdoms, duchies, marches, counties would never be able to stabilize for long. The Holy Roman Empire was most successful, followed by France and England (Remember, Charles V, Francis, and Henry 8 owned almost all of Western Europe, and more), but neither one of these 3 powers was strong enough to outright defeat the others; Europe has a history of warfare to prove that.

In Europe, the biggest unifying force was the church, Christendom later, but that was never strong enough to overcome the Nobles and their titles. Not even Charlemagne was swayed enough to be a true unifier (given the succession).

Either way, when nationalism became a factor, this only solidified the national divides through Europe. Recently, globalized economies and the European Union is making an attempt to unify Europe, but there is still the spectre of nationalism which is the primary force against it. That is deeply engrained in European history and values, it takes a lot longer than a few decades to change an entire cultural system and education. Especially with the confirmation bias against the downside of unification.

So, anyway, in short: title system in medieval Europe prevented it, then later nationalism.
Oct 2013
Languages were never a significant issue, because the only language of importance, was the lingua franca and the language of the administration: Latin for Europe, Classical Chinese for China.
I beg to differ.

The language is an important factor, and a lingua franca is never enough for creating an unity. Especially not a dead language, like Latin.
Mar 2012
Yang Jian being a Han is just semantics, as Southern "Chinese" never related to the Han ethnic identity, instead we have different groups of people speaking sinitic languages with a shared culture. The Roman west spoke Romance language, but the Roman east spoke mostly Greek. So in that China is somewhat more homogeneous, but that is hardly the prominent determinant factor. People like Justinian only came close to reunifying the Roman Empire, so they are not comparable to Sui Wendi. There were several Chinese generals before Yang Jian who were partially successfully or also came close to unifying China. The Eastern Jin general Huan Wen managed to reconquer Luoyang in 356, after Ran Wei was overran by Former Yan. Then the Former Qin thrust southwards took Sichuan, and only after being defeated at Feishui in 383 did Fu Jian's ambition break. Fu Jian also took the entirety of the Tarim Basin and even extended his rule into north of the Gobi in Mongolia, hence his empire was not significantly smaller than the Eastern Han in the 2nd century. After Fu Jian's defeat, the Eastern Jin general Liu Yu took almost the entire Northern China outside of Hebei (and Hexi or Gansu corridor, which wasn't even a formal part of the central plains), defeating the Tuoba Wei in Hebei and then went back to overthrow the Jin dynasty and establish the Liu Song. The Jin conquests were then lost to the Xia regime from Ordos.