Tennōki (天皇記, Record of the Emperor), alternatively known as Sumera Mikoto no Fumi, is a historical text purported to have been written in 620 by Shōtoku Taishi and Soga no Umako. It is recorded in the Nihon Shoki, but no extant copies are known to exist.
According to the Nihon Shoki,
The historiography of Japan (日本史学史 Nihon shigakushi) is the study of methods and hypotheses formulated in the study and literature of the history of Japan.
The earliest work of Japanese history is attributed to Prince Shōtoku, who is said to have written the Tennōki and the Kokki in 620 CE. The earliest extant work is the Kojiki of 712. The Nihon Shoki followed by 720. These two works formed the base of a history of the nation based in great part on Japanese mythology, in particular that of the Shinto religion. The works were inspired by Chinese historiography and were compiled with the support of the Japanese state. Five more works between 797 and 901 completed what had begun with the Nihon Shoki; the six are known as the Rikkokushi ("six national histories").