Before his ascension to the Nanboku-chō throne, his personal name (hisimina) was Kazuhito-shinnō (量仁親王).[2] He was the third son ofEmperor Go-Fushimi of theJimyōin line. His mother was Kōgimon'in Neishi (広義門院寧子). He was adopted by his uncle,Emperor Hanazono. His family included:
Empress: Imperial Princess Yoshiko (懽子内親王) later Senseimon-in (宣政門院),Emperor Go-Daigo’s daughter
Second daughter: (b. 1335)
Third daughter: Imperial Princess Mitsuko (b. 1337; 光子内親王)
Consort: Imperial Princess Hisako (寿子内親王) later Kianmon-in (徽安門院),Emperor Hanazono’s daughter
In his own lifetime, Kōgon and those around him believed that he occupied theChrysanthemum Throne from 22 October 1331[3] until 7 July 1333.[4] Kazuhito-shinnō was namedCrown Prince and heir toEmperor Go-Daigo of theDaikakuji line in 1326. At this time in Japanese history, by decision of theKamakura shogunate, the throne would alternate between theDaikakuji andJimyōin lines every ten years. However, Go-Daigo did not comply with this negotiated agreement.
In 1331, when Go-Daigo's second attempt to overthrow theshogunate became public, the Shogunate seized him, exiled him to theOki Islands, and enthroned Kōgon on 22 October. Emperor Go-Daigo used the 17-petal chrysanthemum emblem during his exile. He escaped Oki in 1333, with the help ofNawa Nagatoshi and his family, and raised an army at Funagami Mountain inHōki Province (the modern town of Kotoura inTōhaku District,Tottori Prefecture). Meanwhile,Ashikaga Takauji (足利 尊氏), the chief general of the Hōjō family, turned against the Hōjō and fought for Emperor Go-Daigo in the hopes of being named shōgun. Takauji attacked Hōjō Nakatomi and Hōjō Tokimasu, theRokuhara Tandai, or chiefs of the Kamakura shogunate in Kyoto. They both fled to the east, but were captured inŌmi Province. On 7 July 1333, Go-Daigo seized the throne from Emperor Kōgon and attempted to re-established Imperial control in what is referred to as theKenmu Restoration (1333–1336). Go-Daigo's attempt failed, however, afterAshikaga Takauji turned against him.
In 1336, Takauji installed Kōgon's younger brother on the throne asEmperor Kōmyō. Go-Daigo fled toYoshino, inYamato Province and continued to lay proper claim to the throne, establishing what would come to be known as theSouthern Court. Kōmyō's court remained in Kyoto and would come to be known as theNorthern Court. This marked the beginning of theNorthern and Southern Courts Period of Japanese history, which lasted until 1392.
In April 1352, taking advantage of a family feud in the Ashikaga clan known as the Kan'ō Disturbance,Emperor Go-Murakami of the Southern Court captured Kyōto, and carried away Emperor Kōgon, Emperor Kōmyō,Emperor Sukō, and the Crown Prince Tadahito. They finally ended up in Anau, the location of the Southern Court.[5]
Following this, Kōgon was held underhouse arrest for the remainder of his life. In his final years, he converted toZen Buddhism, and died on 5 August 1364.
