I find it really interesting that from most of the period from the han dynasty through the song the Chinese did not really reach out of there sphere of influence, thanks to sino centrism they did not undertake too many conquests with the exception of the Tariam Basin and Vietnam and failed to take Korea during the Sui Dynasty.
I would like to see an east asia modified to change the concept of sino centrism to make it more aggressive.
I think of a Chinese Han Dynasty invasion of Southern Japan a near equivalent to the actual roman invasion of Britain
I already stated why it was harder for China to expand further into Korea
in this thread but here's a recap of the main points:
You would first need an emperor that could do the same with Korea. Emperor Wudi of Han conquered Gojoseon and set up four commanderies, but three of them were lost within 25 years. On the other hand, Emperors Wendi of Sui and Taizong of Tang had never lost a campaign until they invaded Goguryeo. In both cases, they were able to take several Goguryeo border fortresses, but failed to advance any further. Had Goguryeo been defeated earlier than in OTL, either the Sui or the Tang would have had to face a probable Baekje-Silla alliance, which would have been hard to conquer based on how Silla repulsed the Tang in OTL.
There's a very good reason why Goguryeo held out against the Sui and Tang for 70 years and six expeditions. Although there was a 30-year break in between, 40 years is still a long time for a state to resist another that was about 10 times its population. All eligible males in Goguryeo were trained to fight in case of a war, so there was no problem with conscription. Goguryeo also either allied with or maintained tributary relations (usually in Goguryeo's favor) with Khitan and Mohe tribes, and also allied with the Turks, urging them to revolt against the Tang so that Goguryeo would have breathing space. In other words, you would need to make sure that Goguryeo would be isolated from its allies, then break through two lines of fortresses to successfully invade Pyongyang, and finally subdue the southern kingdoms. By the time that someone accomplishes or attempts to accomplish this, it's very likely that there would be border issues with bordering states to the north or west, or an uprising protesting against such a long and exhausting campaign or campaigns.
In addition, it would have been hard for the Han to expand further than it did mostly because of the Xiongnu. It was probably the only time that a Chinese dynasty acknowledged another state as its equal, and it took them about 200 years to finally subjugate the nomads. It did temporarily establish commandaries in Central Asia and southern Manchuria/northern Korea, but unless the Chinese migrated in large numbers into either or both regions, it would have been hard for the Han to retain the temporary gains for a significant amount of time. It failed in Central Asia because the environment was mostly inhospitable, and in Korea because of raids from states such as Goguryeo.
It would have been extremely hard for the Tang to perform significantly better than in OTL for similar reasons. It controlled a significant amount of Central Asia as well, but lost most of it after the An Shi Rebellion. It might have been possible to avert the disaster, but I think it would have been highly unlikely for all of the generals to remain loyal when some of them had control over a significant amount of territory and army, not to mention political factors. It would also have been hard for the rulers to maintain control over all of its regions when some of them tried to rebel, and bordering states tried to seize Chinese territory. Although the Tibetans sacked the capital after the dynasty was greatly weakened, the fact that foreigners were able to temporarily seize control of the political center suggests that the Tang barely held itself together during its latter years.
Meanwhile, although Goguryeo had been vanquished by the Tang with help from Silla, which was crucial, Balhae was established around the same area only 30 years later. This was probably possible because Wu Zetian had taken control, which meant that the dynasty could have been politically unstable. In addition, Silla was unwilling to help after they recently pushed the Tang out of the Korean peninsula, and because the residents in southern Manchuria were treated harshly, it was hard for the Tang to bring the revolt under control because the various tribes in the region unified in order to push the Chinese out. It's also important to note that around this time, Silla's population was around 6-7 million, while the population of Balhae when it was founded was at least half that number. In other words, their combined population would have been about 1/3 or 1/4 that of the Tang when it lost control of the northeast.
And the Sui actually got away with half of Korea being conquered. The Gorguryeo Kingdom was a rather large thing.
I'm not really sure what you mean by this. The Sui did temporarily conquer several border fortresses, but never held them for long in part because of supply issues, low morale, and the fact that the generals had to report to the emperor right before making an important decision. The situation after each campaign mostly ended in a status quo.
Really? I figured that since the Shang, Zhou, and Warring States were all based in that area, that that was where Chinese civilization began.
During the Warring States Period, the Yan's capital was located around what is now Beijing, but the Yuan was the first unified Chinese dynasty to have its capital in that location. As other people have stated before, Chinese civilization started around the area between the Yellow River and the Yangtze River. On the other hand, the area around Beijing was probably considered to be part of the northern border by the Chinese until the Ming.
