I agree that they would have recorded more meticulously, but the problem is that the Northern Wei wasn't exactly a Chinese dynasty either. It was a Xianbei state that integrated Chinese customs. I also think they meant that Balhae took what was once Baekje territory, not that Balhae existed during the 400s or 500s.
As I said before, I think what the sources are stating are that Baekje temporarily held territory in what is now Manchuria, with a remote possibility of other cities in Shandong and the rest of the Chinese coastline, because the latter are not mentioned in the sources. I could be mistaken in the following assumptions, but Baekje probably held territory in the northern parts of the Liao river, or they could have lost effective control by the time the Sui unified China.
The problem with assuming that Baekje was mistaken for Buyeo is that Buyeo was probably limited to the southeast corner of Manchuria, and Balhae most likely never held territory in Shandong, much less the Liaodong peninsula. I agree that my assumption of Baekje having control around the Liao river is unlikely, but I think it is also not a coincidence that several Chinese sources state that Baekje probably held territory near or in Manchuria in addition to the southwest corner of the Korean peninsula.
Although the Samguk Sagi is a trustworthy source, the problem is that it was written about 6-700 years after the conflicts were over, and because Silla, which was confined to the peninsula, technically "unified" the three kingdoms, the source could have been biased toward the victorious states.
Hmm, I think Balhae did have territory on or near the Liaodong Peninsula. I mean, did the Khitan Liao first gain a boundary with Koryo after they took over Balhae? Also, I feel like we need more people to discuss the issue. Besides you and Sumeragi, it doesn't seem like there are that many people who are passionate about Korean history.
I'm trying not to flog a dead horse here or sound like a broken record here. My position is fairly simple:
- There is no archaeological evidence that Baekje held territory on the Chinese mainland. I think you agree with this.
- There is no literary evidence that states Baekje held parts of the Chinese mainland. This is where I understand there's more disagreement.
My evidence is a bit more complex.
The
Qi Shu and
Zizhi Tongjian describes a battle between Northern Wei and Baekje in roughly 488. Not once do either texts describe the location of this battle. Wikipedia says that the generals who were awarded with areas that sounded like Liaoxi area names. It cites the
Qi Shu, so there is no proof that the places cited are Liaoxi area names. Wikipedia also says Northern Wei could not have crossed through hostile Goguryo territory to attack the Baekje holdings in Korea. This is true. It does not logically follow, however, that Northern Wei was unable to attack Baekje via a naval force. It does not logically follow either that Northern Wei must have attacked Baekje territories in China, in Liaoxi or Hebei. The source for the
Qi Shu is a Baekje embassy to the court of Southern Qi. It does not logically follow that this embassy must be telling the truth. I am not saying these sources are lying: the fact other sources mention this battle suggests it took place (some say it was a Wei victory). I am asserting, however, that none of these sources say that this battle took place on the Chinese mainland in Baekje territory.
Also, other sources from the same period do not describe Baekje holdings in China, not in Liaoxi, and not in Shandong, and not along the coastline either. Northern Wei was not ruled by native Han Chinese, but it was a Chinese dynasty in the same way as the Yuan or Qing. There is no reason to assume that its records would expunge entire Baekje holdings on the Continent.
(I know I say "Wikipedia says" several times, but I do not aim to make a strawman argument, it's just that you mentioned Wikipedia several times. However, I do not desire to rebut arguments drawn from there. If you have views separate from Wikipedia's statements, please tell me.)
I also agree, yes, that Balhae never controlled parts of Shandong. Nor is there proof that any other Korean states did either. Shandong is part of the Chinese heartland. Records can be lost, but the cultural memory of occupation is not so easy to lose. No records state that Shandong or the Chinese coastline was controlled by the peoples of Baekje or Balhae.
The last issue is the idea that Baekje held territory in Manchuria. As I mentioned earlier regarding the Baekje-Wei conflict, none of the five sources that describe this conflict state that it occurred on the Chinese mainland. However, Manchuria during this time was not exactly the center of civilization. The idea, then, is that Baekje might have had territory along the Liao River. This seems to be supported by the
Song Shu, the
Liang Shu and the
Jin Shu, which all reference Baekje. Again, looking at Wikipedia, it becomes clear that this does not necessarily prove the idea Baekje held territory along the Liao. Apparently the
Jin Shu says an alliance of Goguryo, Baekje, and the Xianbei took military action. But this is no proof of Baekje territory in the area. If the opposite was true, scholars in the future might argue that the Republic of Korea's ISAF contingent is proof that Korea had territory in Afghanistan! The
Jin Shu says that in roughly 345 the people of Baekje posed a threat to the stability of Liaoxi. When this was written (in the seventh century) it was thought the rulers of Baekje were descendants of the Puyo. It would thus make more sense that the writer was projecting backwards, and made a mistake when he thought Baekje had territory in Liaoxi, when it was really the people of Puyo. The second example, from the
Zizhi Tongjian, says that in roughly 346 the people of Baekje attacked Puyo and forced the people of Puyo westwards towards Liaodong and Liaoxi. Jonathan Best follows Mark Byington's suggestion that this attack was really by Goguryo or the Yilou. It makes no sense that Baekje attacks the Puyo, and the Puyo flee towards the Baekje and into Liaoxi. It makes much more sense that the
Zizhi Tongjiang was mistaken. These are the two earliest references to Paekje. Kim Pusik, the author of the
Samguk Sagi, uses the
Jin Shu and
Zizhi Tongjian often. He does not cite either of them in relation to the events of 345 and 346. I don't know his mental state when writing. He might have been biased, but he repeats the
Zizhi Tongjian line that mentions the Baekje victory over the Northern Wei. I'll wager that he found the
Jin Shu and
Zizhi Tongjian statements about Baekje in Manchuria unlikely. Thus, the sources which mention Baekje in Manchuria are probably wrong. The other sources mentioned by Wikipedia, like the
Liang Shu or the
Song Shu, probably make this same sort of mistake.
The
Qi Shu, the
Zizhi Tongjian, the
Jiu Tang Shu, the
Xin Tang Shu, the
Liang Shu, the
Song Shu and other histories are not some sort of
Tian Shu, or Book from Heaven. Historians wrote them. These scholars made mistakes. Sometimes they had bad sources. Sometimes they were ideologically influenced. Sometimes they were wrong.
Again, I'm not being dogmatic. I have nothing against the concept of a Korean state holding territory in China. In fact, I acknowledge that with Goguryo and Balhae this was the case. However, my stance is that Paekje did not hold territory on the Chinese mainland, and that references to Paekje in Manchuria are better explained by references to other similar peoples in the area. Now, I have presented my arguments based on what I believe to be are facts. If there are any mistakes you feel I have made, or if you believe I have misrepresented your positions, feel free to tell me. I know I haven't organized my facts very well. I am not here to argue what may be possible: perhaps tomorrow a grave might be discovered in China (maybe in Liaoxi!) with Baekje artifacts and copies of the annals of Baekje and Goguryo, and thus my entire post will look silly and academically outdated. Perhaps it was possible that Baekje controlled parts of the Chinese coast but left absolutely no evidence. Numerous possibilities exist, but only certain facts can be supported with evidence.