The main forces of the Imperial army detected ahead of them about three hundred Emishi/Ezo troops gathered near 'the residence of Aterui, (a chief commander of the Emishi/Ezo forces)', according to "The Chronicle of Japan Continued."
この主力軍は、「賊帥夷、アテルイ（アテルイ）居」（『続日本紀』）のあたりで前方に蝦夷軍約300名を確認した。