Rikkokushi (六国史), also romanized Rokkokushi, is a general term for Japan's six earliest national histories. These six books chronicle the mythology and history of Japan from the earliest times to AD 887.
History
The six histories were written at the Imperial court during the eighth and ninth centuries. These works include
Nihon shoki (Chronicle of Japan, also called Nihongi), 720
Shoku Nihongi (Continued Chronicle of Japan, also called Shokki), 797