陣が平城跡出土の瓦質土器・擂鉢片に関する一考察

In this paper I discussed the earthenware-motor materials excavated through disaster recovery work during the 2019 fiscal year. The earthenware-motor piece is very similar to the "Bo-Cho typed motor (防長型擂鉢)" which were excavated in areas under the control of the Suo-Ouchi clan (周防大内氏) in the Middle Ages, mainly in present-day Yamaguchi Prefecture. This motor piece was excavated from the ruins of the Jingahira Castle (陣が平城跡) in Saijo-cho,Higashihiroshima City, which is adjacent to the north side of a national historic site: the Kagamiyama Castle ruins (鏡山城跡) . Kagamiyama Castle was the center of the "To-saijo (東西条)" region where the Suo-Ouchi clan were and the base of the Aki country (安芸国) rule. Jingahira Castle was traditionally believed to be where the army of the Izumo-Amago clan (出雲尼子氏) put up a camp when they captured Kagamiyama Castle in 1523. However ,considering the similarity of the territorial structure (縄張り構造) of castle, the Jingahira Castle was likely to be built by the Ouchi clan just like with the Kagamiyama Castle. And that seems to support the similarity of the earthenware-motor piece excavated at Jingahira Castle ruins to the "Bo-Cho typed motor".