大鎧は、様式的に11世紀には成立していたと考えられる。ここでは、大鎧の成立過程を「小札」の威孔、綴孔の配置の変化と威方、綴方の変遷という視点から、考察した。その結果、古代のⅡ類、2行16孔の小札が、平安期の戦闘のなかで威孔などの配置が変化、省略されて大鎧初期の四目札への代わり、さらに威方が縦取威から縄目取威へと変化することで2行13孔の並札が成立したという変遷過程を復元した。また、Ⅱ類の小札は、古墳時代からユーラシア東部、極東地域との密接な関連を持つ小札であり、鎧の構造においても、相互に影響があった可能性も指摘した。New Synthesis on the Origin of Oyoroi Armor in terms of Lamellae.
The Oyoroi armor is highly valued as the full bloom (florescence) of artisanship in the Japanese art history. The armor is considered to have appeared at least in the 11th century, i.e. middle Heian period. However, because the intact specimens of the Oyoroi of that date have been rarely preserved, the origin still remains ambiguous. The explanation for the evolution of lamellae has a possibility to shed a light on this question. As parts of the Oyoroi, 3 types of lamellae, Yotsume-zane, Mitsume-zane and Nami-zane were exploited. Lacing methods of them are divided into 2 types, one is Tatedori-odoshi (vertical lacing with lamellae above) and the other is Nawamedori-odoshi (oblique lacing with lamellae above) (fig6,7,10).
The similar arrangement for lacing and binding holes between the type ll lamellas from Akitajo (8th century) (fig3) and those discovered in the Maritime region of Russia (fig4), should have been a result of some kind of trading or diplomatic relationships as historical records (for example Shoku-Nihongi) had referred to. This type ll lamellae is a dominant candidate of the Oyoroi lamellae, because the earliest examples of it (Yotsume-zane for Tatedori-odoshi) show almost same arrangement of lacing and biding holes with those of type ll lamellae. Each has 2 vertical rows of 16 or 14 lacing and binding holes at the both sides of the lamellas (fig9).
With regard to the methods of the lacing, the Nawamedori-odoshi is duly supposed to have been developed from Tatedori-odoshi. Consequently, the Nami-zane lamellae for Oyoroi, with 13 holes arrayed in double vertical rows, is hypothesized to have been evolved from the type ll lamellae at Akitajo with 16 holes in double rows through the Yotsume-zane lamellae with 14 holes in double rows during the Heian period associated with the rise of Samurai worriers (fig10).