Southern Court The were a set of four emperors ( Emperor Go - Daigo and his line ) whose claims to sovereignty during the Nanboku - chō period spanning from 1336 through 1392 were usurped by the Northern Court . This period ended with the Southern Court definitively losing the war , and they were forced to completely submit sovereignty to the Northern Court . This had the result that while later Japanese sovereigns were descended from the Northern Court , posterity assigns sole legitimacy during this period to the Southern Court . Nanboku - chō overview . The genesis of the Northern Court go back to Emperor Go - Saga , who reigned from 1242 through 1246 . Go - Saga was succeeded by two of his sons , Emperor Go - Fukakusa and Emperor Kameyama , who took turns on the throne . This because on his death bed in 1272 , Go - Saga had insisted that his sons adopt a plan in which future emperors from the two fraternal lines would ascend the throne in alternating succession . This plan proved to be unworkable , resulting in rival factions and rival claimants to the throne . Go - Fukakusa ' s descendants were referred to as the while Kameyama ' s descendants were known as the . Northern Court . In 1333 , when Emperor Go - Daigo ( from the Daikakuji - tō ) staged the Kemmu Restoration and revolted against the Kamakura shogunate , the Shōgun responded by declaring Emperor Kōgon , Go - Daigo ' s second cousin once removed and the son of an earlier emperor , Emperor Go - Fushimi of the " Jimyōin - tō " , as the new emperor . After the destruction of the Kamakura shogunate in 1333 , Kōgon lost his claim , but his brother , Emperor Kōmyō , and two of his sons were supported by the new Ashikaga shoguns as the rightful claimants to the throne . Kōgon ' s family thus formed an alternate Imperial Court in Kyoto , which came to be called the Northern Court because its seat was in a location north of its rival . During the Meiji period , an Imperial decree dated March 3 , 1911 established that the legitimate reigning monarchs of this period were the direct descendants of Emperor Go - Daigo through Emperor Go - Murakami , whose had been established in exile in Yoshino , near Nara . The established in Kyoto by Ashikaga Takauji is therefore considered illegitimate . Northern Pretenders . These are the " Hokuchō " or Northern Court emperors : The Imperial Court supported by the Ashikaga shoguns was rivaled by the of Go - Daigo and his descendants . This came to be called the Southern Court because its seat was in a location south of its rival . Although the precise location of the emperors ' seat did change , it was often identified as simply Yoshino . In 1392 , Emperor Go - Kameyama of the Southern Court was defeated and abdicated in favor of Kōgon ' s great - grandson , Emperor Go - Komatsu , thus ending the divide . The Southern Court of the Japanese Imperial Line is nonetheless seen as legitimate . In fact , Northern Court members are officially called pretender s . One Southern Court descendant , Kumazawa Hiromichi , declared himself to be Japan ' s rightful Emperor in the days after the end of the Pacific War . He claimed that Emperor Hirohito was a fraud , arguing that Hirohito ' s entire line is descended from the Northern Court . Despite this , he was not arrested for lèse majesté , even when donning the Imperial Crest . He could and did produce a koseki detailing his bloodline back to Go - Daigo in Yoshino , but his claims and rhetoric failed to inspire anything other than sympathy . Southern Court Emperors . These are the " Nanchō " or Southern Court emperors : Re - unification of Imperial Courts . Go - Kameyama reached an agreement with Go - Komatsu to return to the old alternations on a ten - year plan . However , Go - Komatsu broke this promise , not only ruling for 20 years , but being succeeded by his own son , rather than by one from the former Southern Court .