Nihonkoki History Book is a collection of histories created by imperial command; it was compiled in the early Heian period after Shoku-Nihongi (Continuation of Chronicles of Japan), being the third volume of Rikkokushi (Six National Histories).
日本後紀（にほんこうき）は、平安時代初期に編纂された勅撰史書で、続日本紀に続く六国史の第三にあたる。