Before his ascension to the Nanboku-chō throne, his personal name (his imina) was Kazuhito-shinnō (量仁親王).[2] He was the third son of Emperor Go-Fushimi of the Jimyōin line. His mother was Kōgimon'in Neishi (広義門院寧子). He was adopted by his uncle, Emperor Hanazono. His family included:
In his own lifetime, Kōgon and those around him believed that he occupied the Chrysanthemum Throne from October 22, 1331[3] until July 7, 1333.[4] Kazuhito-shinnō was named Crown Prince and heir to Emperor Go-Daigo of the Daikakuji line in 1326. At this time in Japanese history, by decision of the Kamakura shogunate, the throne would alternate between the Daikakuji and Jimyōin lines every ten years. However, Go-Daigo did not comply with this negotiated agreement.
In 1331, when Go-Daigo's second attempt to overthrow the shogunate became public, the Shogunate seized him, exiled him to the Oki Islands, and enthroned Kōgon on October 22. Emperor Go-Daigo used the 17-petal chrysanthemum emblem during his exile. He escaped Oki in 1333, with the help of Nawa Nagatoshi and his family, and raised an army at Funagami Mountain in Hōki Province (the modern town of Kotoura in Tōhaku 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, the Rokuhara Tandai, or chiefs of the Kamakura shogunate in Kyoto. They both fled to the east, but were captured in Ōmi Province. On July 7, 1333, Go-Daigo seized the throne from Emperor Kōgon and attempted to re-established Imperial control in what is referred to as the Kenmu Restoration (1333–1336). Go-Daigo's attempt failed, however, after Ashikaga Takauji turned against him.
In 1336, Takauji installed Kōgon's younger brother on the throne as Emperor Kōmyō. Go-Daigo fled to Yoshino, in Yamato Province and continued to lay proper claim to the throne, establishing what would come to be known as the Southern Court. Kōmyō's court remained in Kyoto and would come to be known as the Northern Court. This marked the beginning of the Northern 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 under house arrest for the remainder of his life. In his final years, he converted to Zen Buddhism, and died on August 5, 1364.
