, also known as Ninnan, was a after Eiman and before Kaō. This period spanned the years from August 1166 through April 1169.Nussbaum, Louis-Frédéric. (2005). "Nin'an" in ; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, see .Titsingh, Isaac. (1834). Brown, Delmer et al. (1979). Gukanshō, pp. 329-330; Varley, H. Paul. (1980). Jinnō Shōtōki. p. 212.
Change of era
February 3, 1166 <!-- NengoCalc 仁安一年一月一日 -->: The new era name was created to mark an event or series of events. The previous era ended and a new one commenced in Eiman 2, on the 27th day of the 8th month of 1166.
Events of the Nin'an era
1168 (Nin'an 3, 2nd month ): Rokujō was deposed at age 5, and he received the title Daijō-daijin tennō.
March 30, 1168 (Nin'an 3, 19th day of the 2nd month)<!-- NengoCalc 仁安三年二月十九日 -->: In the 3rd year of Rokujō-tennō 's reign (六条天皇3年), the emperor was deposed by his grandfather, and the succession (senso) was received by his cousin, the third son of the retired-Emperor Go-Shirakawa. Sometime thereafter, Emperor Takakura is said to have acceded to the throne (sokui), and he is proclaimed emperor.Titsingh, Brown, p. 330; Varley, p. 44; a distinct act of senso is unrecognized prior to Emperor Tenji; and all......