was a after Manju and before Chōryaku. This period spanned the years from July 1028 through April 1037.Nussbaum, Louis-Frédéric. (2005). "Chōgen" in ; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, see . The reigning emperors were and .Titsingh, Isaac. (1834). Annales des empereurs du Japon, pp. 156-159; Brown, Delmer et al. (1979). Gukanshō, pp. 307-310; Varley, H. Paul. (1980). Jinnō Shōtōki. p. 195-196.
Change of era 1028 : The new era name Chōgen was created to mark and event or series of events. The previous era ended and the new one commenced in Manju 5, on the 25th day of the 7th month.Bruce, p. 310.
Events of the Chōgen era Chōgen 9, on the 17th day of the 4th month (1036): In the 9th year of Emperor Go-Ichijō's reign (後一条天皇9年), he died; and the succession (senso) was received by his son.Brown, p. 310; Varley, p. 44; a distinct act of senso is unrecognized prior to Emperor Tenji; and all sovereigns except Jitō, Yōzei, Go-Toba, and Fushimi have senso and sokui in the same year until the reign of Emperor Go-Murakami. Chōgen 9, in the 7th month (1036): Emperor Go-Suzaku is said to have acceded to the throne (sokui).Titsingh, p. 160; Varley, p. 44.
Notes
References Brown, Delmer M. and Ichirō Ishida, eds. (1979). Gukanshō: The Future and the Past. Berkeley: University of California Press. ; OCLC 251325323 Nussbaum, Louis-Frédéric and Käthe Roth. (2005). Japan encyclopedia. Cambridge: Harvard University Press. ; OCLC 58053128 Titsingh, Isaac. (1834). Nihon Odai Ichiran; ou, Annales des empereurs du Japon. Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691 Varley, H. Paul. (1980). A Chronicle of Gods and Sovereigns: Jinnō Shōtōki of Kitabatake Chikafusa. New York: Columbia University Press. ; OCLC 6042764
External links National Diet Library, "The Japanese Calendar" -- historical overview plus illustrative images from library's collection