倭と栄山江流域の交流史を考える場合，文献的に問題となるのは，まず全羅南道および耽羅の百済への服属時期を確定することが必要と思われる。そのうえで北九州系および畿内系などに細分化される倭人の移住集団の活動内容の分析が必要となる。さらには加耶地域への移住集団との対比も必要となる。以下ではこの問題を考える素材として『日本書紀』欽明紀に散見する倭系百済官僚を中心に検討した。現在，栄山江流域の前方後円墳被葬者についての諸説は，大きくは在地首長あるいは土着勢力とする説，倭人あるいは倭系の人物を被葬者とする説に分かれている。本稿では在地的な首長系列とは異なる地点に突如出現する点を重視して，後者の可能性を指摘した。結論として，憶測を述べるならば五世紀後半以降の一時期に限定される栄山江流域の前方後円墳被葬者像として，百済王族たる地名王・侯の配下で，県城以下クラスの支配を任された，北九州を含む倭系豪族と想定した。彼らはやがて，百済の都に集められて官僚化し，倭国との外交折衝などに重用されたために，一時的な現象として古墳は消滅したのではないか。栄山江流域にのみ前方後円墳が集中する理由や，移住の詳細なプロセスなどについては不明であり，今後も検討する必要がある。

When thinking of the history of exchanges between Old Japan and the Yeongsan River Basin, what emerges as an issue of document, is that it will first be necessary to confirm the period when the Cholla-Namdo (South Cholla Province) and the Tamna yielded allegiance to Baekje. Further, it will be essential to analyze the content of the activities of the migrant groups of Wajin who were subdivided into the Kitakyushu lineage and the Kinai lineage. Besides, it will also be necessary to compare with the groups migrating to the Gaya region. Below we examine by focusing on the Japanese government officials of Baekje whom one comes across occasionally in the Kinmei period of "Nihon Shoki" (Chronicles of Japan) that is used as material to discuss this issue.Currently, theories about persons buried in the large zenpo-koen-fun or keyhole-shaped tomb mounds of the Yeongsan river basin are broadly divided into the theory that considers the local heads or the indigenous people and the theory that considers the Wajin or the people of the Wa lineage as those buried in the tombs. In this paper, we suggest the possibility of the latter, emphasizing the fact that they appear abruptly at sites different from the ones of local chieftains' lineage.In conclusion, if we speculate, we can assume that the figures of persons buried in the zenpo-koen-fun of the Yeongsan river basin that are limited to a specific period since late 5th century were the powerful Wajin families. They were entrusted with the rule of the classes inferior to those of the prefectural castle under the Baejke royal family who were kings of the place or followers of warlords, including in Kitakyushu. As they eventually gathered in the capital of Baejke before long, were bureaucratized, and were promoted to responsible posts including diplomatic negotiations with Wa, the Kofun may have disappeared as a temporary phenomenon. The reasons the zenpo-koen-fun were concentrated solely in the Yeongsan river basin or the detailed process of the migration are unclear, and there is a need to examine this in the future.

source:https://www.rekihaku.ac.jp/outline/publication/ronbun/ronbun9/index.html#no217