Kagen (嘉元) was a Japanese era name (年号, nengō, lit. "year name") after Kengen and before Tokuji. This period spanned the years from August 1303 through December 1306.[1] The reigning emperor was Go-Nijō-tennō (後二条天皇).[2]
1303Kagen gannen (嘉元元年): The new era name was created to mark an event or series of events. The previous era ended and the new one commenced in Kengen 2. The era name is derived from the Yiwen Leiju (AD 624) and combines the characters 嘉 ("auspicious") and 元 ("foundation").
July 17–27, 1303 (Kagen 1, 13th-23rd days of the 6th month): A white comet ("broom star") was seen at azimuth in the northeast each day at dawn for 10 days.[3]
October 4, 1305 (Kagen 3, 15th days of the 9th month): Former Emperor Kameyama's death.[4]
Pankenier, David W., Zhentao Xu and Yaotiao Jiang. (2008). Archaeoastronomy in East Asia: Historical Observational Records of Comets and Meteor Showers from China, Japan, and Korea. Amherst, New York: Cambria Press. ISBN9781604975871ISBN1604975873; OCLC 269455845