Imperial Regalia of Japan in the context of "Ninigi-no-Mikoto"

The Nanboku-chō period (南北朝時代, Nanboku-chō jidai), also known as the Northern and Southern Courts period, was a period in Japanese history between 1336 and 1392, during the formative years of the Muromachi (Ashikaga) shogunate. During this time, two opposing Imperial courts and their respective claimants as Emperor were engaged in conflict over their claims to the Chrysanthemum Throne, with the Southern Court ultimately renouncing their claim in favor of the Northern Court in 1392. This period became a source of contention for many Japanese historians and scholars over the following centuries. Initially, the North's victory in the dispute led official histories to paint them as the legitimate claimants. In reality, the Northern pretenders were simply puppet rulers under the direct control of the Kamakura and Ashikaga shogunates, while the Southern claimants maintained control of the Japanese Imperial Treasures, the sacred artifacts that confirmed an Emperor's legitimacy. To officially resolve this historical dilemma, in 1911 Emperor Meiji issued an edict that the Emperors of the Southern Court were the legitimate claimants during this period.

The destruction of the Kamakura shogunate of 1333 and the failure of the Kenmu Restoration in 1336 opened up a legitimacy crisis for the new shogunate. Institutional changes in the estate system (shōen) that formed the bedrock of the income of nobles and warriors altered the status of the various social groups. The establishment of the Ashikaga shogunate broadened the economic base of the warriors, while undercutting the noble proprietors. However, this trend had started already with the Kamakura bakufu.

The Northern Court (北朝, hokuchō), also known as the Ashikaga Pretenders or Northern Pretenders, were a set of six pretenders to the throne of Japan during the Nanboku-chō period from 1336 through 1392. Even though the present Imperial House of Japan is descended from the Northern Court emperors, The Southern Court is considered the legitimate line, with the argument being that it was the Southern court which possessed the Imperial Regalia, which was later handed over to the Northern court, thus making Emperor Go-Komatsu the 100th Emperor of Japan. It was in 1911 that Emperor Meiji passed an edict which made the Southern line the legitimate one. Before this, pre-Meiji scholars considered the Northern line as the legitimate line.

The Northern dynasty is also referred to as the "senior line" or the Jimyōin line (持明院統, Jimyōin-tō); Jimyō-in was a temple and retirement residence of this line's emperors Go-Fukakusa and Fushimi.

The Enthronement ceremony (即位の礼, Sokui no rei) is an ancient ceremony that marks the accession of a new emperor to the Chrysanthemum Throne. The Three Sacred treasures are given to the new sovereign during the course of the rite. It is the most important out of the Japanese Imperial Rituals. The most recent enthronement was that of Emperor Naruhito on 22 October 2019.