Chōgen

964–968	Kōhō
968–970	Anna
970–973	Tenroku
973–976	Ten'en
976–978	Jōgen
978–983	Tengen
983–985	Eikan
985–987	Kanna
987–988	Eien
988–990	Eiso
990–995	Shōryaku
995–999	Chōtoku
999–1004	Chōhō
1004–1012	Kankō
1012–1017	Chōwa
1017–1021	Kannin
1021–1024	Jian
1024–1028	Manju
1028–1037	Chōgen
1037–1040	Chōryaku

806–810	Daidō
810–824	Kōnin
824–834	Tenchō
834–848	Jōwa
848–851	Kashō
851–854	Ninju
854–857	Saikō
857–859	Ten'an
859–877	Jōgan
877–885	Gangyō
885–889	Ninna
889–898	Kanpyō
898–901	Shōtai
901–923	Engi
923–931	Enchō
931–938	Jōhei
938–947	Tengyō
947–957	Tenryaku
957–961	Tentoku
961–964	Ōwa

645–650	Taika
650–654	Hakuchi
686–686	Shuchō
701–704	Taihō
704–708	Keiun
708–715	Wadō
Nara
715–717	Reiki
717–724	Yōrō
724–729	Jinki
729–749	Tenpyō
749	Tenpyō-kanpō
749–757	Tenpyō-shōhō
757–765	Tenpyō-hōji
765–767	Tenpyō-jingo
767–770	Jingo-keiun
770–781	Hōki
781–782	Ten'ō
782–806	Enryaku

Chōgen (長元) was a Japanese era name (年号, nengō, lit. "year name") after Manju and before Chōryaku. This period spanned the years from July 1028 through April 1037.^[1] The reigning emperors were Go-Ichijō-tennō (後一条天皇) and Go-Suzaku-tennō (後朱雀天皇).^[2]

Change of era

1028 Chōgen gannen (長元元年): 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.^[3]

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.^[4]
Chōgen 9, in the 7th month (1036): Emperor Go-Suzaku is said to have acceded to the throne (sokui).^[5]

Notes

^ Nussbaum, Louis-Frédéric. (2005). "Chōgen" in Japan Encyclopedia, p. 118, p. 118, at Google Books; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, see Deutsche Nationalbibliothek Authority File.
^ 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.
^ Bruce, p. 310.
^ 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.
^ Titsingh, p. 160; Varley, p. 44.