The Kofun era and early state formationelites as a sign of alliance, friendship, or loyalty to the Yamato chieftain. Indeed, archaeologists
find one- half, one- third, or one- sixth copies of the Hashihaka mounded tomb in the present- day
Okayama and Kyoto prefectures.^3
In addition to a construction plan, the Yamato chieftain also distributed bronze mirrors,
referred to as sankaku- buchi-shinju- kyō (“triangular- rimmed mirrors with deity and beast pat-
terns”), cast from the same mold to local elites. Kobayashi Yukio (1911–1989) developed an
influential hypothesis that the Yamato chieftain distributed these mirrors as a sign of recogni-
tion of allegiance. Kobayashi also argued that the idea that Yamato chieftains utilized their
diplomatic ties with China to distinguish themselves from other elites, and that the spatial
distribution of these mirrors—concentrated in the Nara, Kyoto, and Osaka region, where the
central court is presumed to have been located—serves as evidence for the existence of a strong
central polity that controlled local regions.^4 At present, archaeologists debate whether they
were manufactured in Wei China or in Japan by Chinese craftsmen. The latter possibility
would undermine Kobayashi’s reasoning concerning the importance of the Yamato chieftain’s
China connections. Nevertheless, his argument on the spatial distribution of bronze mirrors
remains convincing.
Debate over state formation: historians’ contributions
The distribution of standardized, keyhole- shaped tombs across most of Japan, as well as the dis-
tribution of sankaku- buchi-shinju- kyō and, in the Middle Kofun era, of iron armor presumably
produced in the center, suggest that a centralized state was already emerging in the Early Kofun
era. Japanese archaeologists and historians today agree that Japanese political organization
evolved toward statehood during the Kofun period, but they hotly debate when it crossed the
threshold into a state- level polity.
The major points of contention are the extent to which society in the Kofun era was central-
ized, and the extent of Yamato control over other regions. On one side of the controversy are
scholars, such as Kobayashi Yukio, who argue that a strong central polity emerged during the
Early Kofun era. On the other, are those, including myself, who contend that local polities
remained relatively autonomous until much later, and that socio- political organization did not
reach the level of a state until the seventh century.^5
Prior to 1991, the only archaeological studies that directly addressed the question of state
formation in Japan were Kobayashi Yukio’s Kofun jidai no kenkyū (1961) and Kondō Yoshirō’s
(1925–2009) Zenpō-kōen-fun no jidai (1983). All other contributions to understanding the forma-
tion of Japanese states were made by historians.
It is also important to note that Marxist perspectives dominated studies of Japanese archae-
ology and ancient history until the 1980s. Japanese scholars in the 1970s and 1980s were preoc-
cupied with Engels’ definition of the state, as outlined in his The Origin of the Family, Private
Property, and the State, and tended to focus on four attributes that must be present in order for an
entity to be properly called a state: the grouping of members on a territorial basis, the institution
of a public force, the power of taxation, and the existence of officials standing above society.
Those who believe that Kofun era society was not a state- level civilization place it instead at
the upper end of Engels’ barbarism stage of development. Historians have used the concept of
“tribal confederacy” (analogous to the Iroquois Confederacy in North America) to describe this
stage.^6 Indeed, Kondō’s aforementioned Zenpō-kōen-fun no jidai discusses social evolution from
the Early Yayoi era to the end of the Kofun period, describing Kofun- era society as a tribal con-
federacy based on kinship or quasi- kinship ties. For Kondō, the shared keyhole shape of the
burial mounds was a reflection of kinship or quasi- kinship ties.