His mother was Princess Inoe, a daughter of Emperor Shōmu; but instead of Osabe, it was Kammu who was later named to succeed their father.

[19] Earlier Imperial sponsorship of Buddhism, beginning with Prince Shōtoku (574–622), had led to a general politicization of the clergy, along with an increase in intrigue and corruption.

[25] Indeed, there was a steady stream of edicts issued from 771 right through the period of Kūkai's studies which, for instance, sought to limit the number of Buddhist priests, and the building of temples.

Also in 789 there was a severe drought and famine—the streets of the capital were clogged with the sick, and people avoiding being drafted into the military, or into forced labour.

These commentaries used political rhetoric to promote a state in which the Emperor, as "Son of Heaven," should extend his sphere of influence to barbarous lands, thereby gladdening the people.

[citation needed] Kammu also sponsored the travels of the monks Saichō and Kūkai to China, from where they returned to found the Japanese branches of, respectively, Tendai and Shingon Buddhism.

[citation needed][27] Kugyō (公卿) is a collective term for the very few most powerful men attached to the court of the Emperor of Japan in pre-Meiji eras.

During Kammu's reign, this apex of the Daijō-kan included: When the daughter of a chūnagon became the favored consort of the Crown Prince Ate (later known as Heizei-tennō), her father's power and position in court was affected.

[33] According to the Shoku Nihongi, Emperor Kammu's mother, Takano no Niigasa (720–90), is a descendant of Prince Junda, son of Muryeong, who died in Japan in 513 (Nihon Shoki, Chapter 17).

Unless otherwise noted (as BC), years are in CE / AD  * Imperial Consort and Regent Empress Jingū is not traditionally listed.