Emperor Go-Komatsu (後小松天皇, Go-Komatsu-tennō; 1 August 1377 – 1 December 1433) was the 100th emperor of Japan, according to the traditional order of succession, and the sixth and final Emperor of the Northern Court.
He is officially considered to have been the Northern pretender from 24 May 1382 to 21 October 1392, when upon Emperor Go-Kameyama's abdication, Go-Komatsu is understood to have been a legitimate emperor (the 100th sovereign) from that date. In 1392, following the post-Nanboku-chō unification of the two formerly contending courts, the Southern Emperor Emperor Go-Kameyama reached an agreement with Go-Komatsu to alternate control of the throne between the Northern and Southern courts on a ten-year plan which effectively signaled the end of the southern court's claims to sovereignty. However, Go-Komatsu reneged, not only ruling for 20 years until his own abdication on 5 October 1412, but was succeeded by his own son, rather than by one from the former Southern Court. According to pre-Meiji scholars, Go-Komatsu's reign as a legitimate emperor spanned the years from 1392 through 1412. The present Japanese Imperial Family is descended from the
three Northern Court emperors.
This Nanboku-chō "sovereign" was named after the 9th-century Emperor Kōkō, and go- (後), translates literally as "later." Jien's Gukanshō explains that Kōkō was called "the Emperor of Komatsu". The 14th-century pretender and emperor may be called the "later Emperor Kōkō" or the "later Emperor Komatsu". The Japanese word go has also been translated to mean the "second one;" and in some older sources, this would-be emperor may be identified as "Komatsu, the second", or as "Komatsu II."
Before his accession to the Chrysanthemum Throne, his personal name (his imina) was Motohito-shinnō (幹仁親王).
Go-Komatsu was the first son of Emperor Go-En'yū. His mother was Tsūyōmonin no Itsuko (通陽門院厳子), daughter of the Lord Keeper of the Privy Seal Sanjō Kimitada (三条公忠).
Consort: Hinonishi Motoko (日野西資子, 1384–1440) later Kohan’mon-in (光範門院), Hinonishi Sukekuni's daughter
First son: Imperial Prince Mihito (1401–1428実仁親王) later Emperor Shōkō
Second son: Prince Ogawa (1404–1425; 小川宮), Emperor Shōkō's crown prince
First daughter: Princess Riei (理永女王; 1406–1447)
Lady-in-waiting: Kanrouji Tsuneko (甘露寺経子), Kanrouji Kanenaga's daughter
Naishi: Hinonishi Sukekuni's daughter
Naishi: Shirakawa Suketada's daughter
Naishi: Kohyōe-no-Tsubone (小兵衛局)
Naishi: Unknown (daughter of a retainer from the Southern Court)
He was named after Emperor Kōkō, who had the alternate name Komatsu, because they both returned the throne to their families, in the case of Emperor Go-Komatsu, by defeating his Southern Court rivals, and in the case of Emperor Kōkō, by succeeding his elder brother's grandson, Emperor Yōzei.
In his own lifetime, Go-Komatsu and those around him believed that he occupied the Chrysanthemum Throne from 24 May 1382 until 1412.
He was raised in the turbulent Nanboku-chō period of rival northern and southern courts in the mansion of Hino Sukenori (日野西資教). He succeeded as Northern Emperor upon the abdication of his father, the Northern Pretender Emperor Go-En'yū. With the help of Ashikaga Yoshimitsu, his father ruled as Cloistered Emperor.