- 国立歴史民俗博物館研究報告 = Bulletin of the National Museum of Japanese History (ISSN:02867400)
- vol.185, pp.369-403, 2014-02
1990年代の三角縁神獣鏡研究の飛躍により,箸墓古墳の年代が3世紀中頃に特定され,〈魏志倭人伝〉に見られる倭国と,倭王権とが直結し,連続的発展として理解できるようになった。卑弥呼が倭国王であった3世紀前半には,瀬戸内で結ばれる地域で前方後円形の墳墓の共有と画文帯神獣鏡の分配が始まっており,これが〈魏志倭人伝〉の倭国とみなしうるからである。3世紀初頭と推定される倭国王の共立による倭王権の樹立こそが,弥生時代の地域圏を越える倭国の出発点であり時代の転換点である。古墳時代を「倭における国家形成の時代」として定義し,3世紀前半を早期として古墳時代に編入する。今日の課題は,倭国の主導勢力となる弥生後期のヤマト国の実態,倭国乱を経てヤマト国が倭国の盟主となる理由の解明にある。一方で,弥生後期の畿内における鉄器の寡少さと大型墳墓の未発達から,倭王権は畿内ヤマト国の延長にはなく,東部瀬戸内勢力により樹立されたとの見方もあり,倭国の形成主体に関する見解の隔たりが大きい。こうした弥生時代から古墳時代への転換についても,¹⁴C年代データは新たな枠組みを提示しつつある。箸墓古墳が3世紀中頃であることは¹⁴C年代により追認されるが,それ以前の庄内式の年代が2世紀にさかのぼることが重要である。これにより,纒向遺跡の形成は倭国形成以前にさかのぼり,ヤマト国の自律的な本拠建設とみなしうる。本稿では,上記のように古墳時代を定義するとともに,そこに至る弥生時代後期のヤマト国の形成過程,纒向遺跡の新たな理解,楯築墓と纒向石塚古墳の比較を含む前方後円墳の成立問題など,新たな年代観をもとづき,現時点における倭国成立に至る一定の見取り図を描く。The development of the study on sankakubuchi shinjukyo (triangular-rimmed mirrors decorated with gods and animals) in the 1990s dated the Hashihaka burial mound to around the middle of the third century. This research results revealed a direct connection between the Wa State described in Gishiwajinden (Account of the Wa in History of the Wei Dynasty written by Chinese) and the Wa Sovereignty and enabled to understand them as consecutive development. This is because it can be considered that the proliferation of keyhole-shaped burial mounds and gamontai shinjukyo (mirrors with an image band decorated with gods and animals) throughout the area around the Seto Inland Sea, which can be regarded as the movements of the Wa State described in Gishiwajinden, started when Himiko was queen of the Wa State in the first half of the third century. Therefore, the establishment of the Wa Sovereignty with several coexisting Wa kings can be dated to the beginning of the third century. This starting point of the Wa State, which exceeded the regional boundaries of the Yayoi period, marked a turning point of the age. Defined as "the period of nation building in Wa," the Kofun period can include the first half of the third century as its early stage.Remaining challenges are to get a clear picture of the Yamato State in the Late Yayoi period, as a leading force in the Wa State, and understand why the Yamato State became the leader of the Wa State after the domestic warfare. On the other hand, since there were exceedingly few iron implements and large-scale burial mounds, some researchers consider that the Wa Sovereignty did not follow as an extension of the Yamato State in the Kinai region but was established by an emerging force in the eastern Setouchi region. There are significant differences of opinion on who established the Wa State.With regard to the shift from the Yayoi period to the Kofun period, the carbon-14 dating method is suggesting a new framework. The method can reconfirm the date of the Hashihaka burial mound as around the middle of the third century. More importantly, the Shonai pottery is dated earlier to the second century. This means that the formation of the Makimuku site is also dated earlier to before the birth of the Wa State. Therefore, the site can be regarded as the independent establishment of the base of the Yamato State.Defining the Kofun period as described above, the present article is aimed at giving the latest picture of how the Wa State was established, based on the new view of dating. To this end, the article covers the establishment process of the Yamato State from the Late Yayoi period to the Kofun period and new perspectives on the Makimuku site, as well as examines the development of keyhole-shaped burial mounds including a comparison between the Tatetsuki mound tomb and Makimuku Ishizuka burial mound.