9th-century neologisms

was a after Gangyō and before Kanpyō. This period spanned the years from February 885 through April 889. The reigning emperors were and .

was a after Kōnin and before Jōwa. This period spanned the years from January 824 through January 834. The reigning emperors were and .

Japanese era from 889 to 898

was a after Enryaku and before Kōnin. This period spanned the years from May 806 through September 810. The reigning emperors were and .

was a after Kashō and before Saikō. This period spanned the years from April 851 through November 854. The reigning emperor was .

was a after Ninju and before ''Ten'an.'' This period spanned the years from November 854 through February 857. The reigning emperor was .

Japanese era spanning from January 834 through July 848

was a after ''Ten'an and before Gangyō.'' This period spanned the years from April 859 through April 878. The two reigning emperors were and .

Japanese era spanning from September 810 through January 824

thumb | right | alt=The image shows a portrait of the Emperor Seiwa sitting cross-legged on a beige-coloured mat with blue and orange flowers. The mat is placed on a large bottle-green rug with white criss-cross edges. He is bald, and is wearing a full-sleeve, milky-white kimono-ish robe that drapes right down to his feet. His hands, not visible, are assumed to be in prayer pose under the robe holding a visible red-gold rosary with green tassels. | Portrait of the Emperor Seiwa , also known as Genkei, was a after Jōgan and before Ninna. This period spanned the years from April 877 through Febr

was a after Kanpyō and before Engi. This period spanned the years from April 898 to July 901. The reigning emperor was .

Belief in Slavic Christianity