Reunification of the Northern and Southern Courts (Meitoku Peace Accord) — The End of the Upheaval Embodied by the Japanese Sword

Reunification of the Northern and Southern Courts — formally the Meitoku Peace Accord (Meitoku no Wayaku) — was the event in which, on the 5th day of the intercalary 10th month of Meitoku 3, Ashikaga Yoshimitsu, third shogun of the Muromachi shogunate, brokered the transfer of the Three Sacred Treasures from Emperor Go-Kameyama of the Southern Court to Emperor Go-Komatsu of the Northern Court, ending the 56-year division of the Northern and Southern Courts. This reunification was also an important turning point in the history of Japanese swords, because the sharp increase in sword production and the diversification of sword forms during the Nanboku-chō upheaval (1336–1392) entered a new phase after reunification, moving toward the Muromachi period.

Course of the Division of the Northern and Southern Courts and 56 Years of Upheaval

The division of the Northern and Southern Courts began in Engen 1 (1336), when Ashikaga Takauji rebelled against the Kenmu regime of Emperor Go-Daigo. At the Battle of Minatogawa (1336), Kusunoki Masashige was defeated and killed, and Takauji occupied Kyoto and installed Emperor Kōmyō as the Northern Court. Emperor Go-Daigo fled to Yoshino (Nara) and established the Southern Court, asserting that the Southern Court held the Three Sacred Treasures. From then on, the Northern Court (the Muromachi shogunate) and the Southern Court repeatedly launched offensives against each other, and the upheaval continued for more than half a century. Through a complex course of events, including the Kannō Disturbance (1350–1352) and the Shōhei Unification (1351), reunification was finally achieved through Yoshimitsu's political skill.

Ashikaga Yoshimitsu's Diplomacy — Transfer of the Three Sacred Treasures and the Southern Court's Return to the Capital

In negotiations with the Southern Court, Ashikaga Yoshimitsu proposed alternating succession to the throne (ryōtō tetsuritsu) (the Northern and Southern Courts taking turns in providing emperors), the grant of provincial public lands (kokugaryō) to the Southern Court, and the transfer of the Three Sacred Treasures as conditions. Emperor Go-Kameyama left Yoshino carrying the Three Sacred Treasures and entered Daikaku-ji in Kyoto on the 2nd day of the intercalary 10th month of Meitoku 3. On the 5th day of the same intercalary 10th month, the Treasures were moved from Daikaku-ji to Emperor Go-Komatsu's Tsuchimikado Palace. Thus, after 56 years, the imperial court was united once more, and the Northern and Southern Courts period nominally came to an end. In practice, however, the promise of alternating succession was not kept. In Ōei 19 (1412), Emperor Go-Komatsu abdicated in favor of Emperor Shōkō, and the throne remained with the Northern line. Cloistered Emperor Go-Kameyama left Saga in Ōei 17 (1410) and moved to Yoshino, and resistance from the Southern line continued sporadically after that.

Japanese Swords and Sword Culture of the Nanboku-chō Era — Transformation After Reunification

The impact of the Reunification of the Northern and Southern Courts on the history of swords was significant. During the 56 years of intense upheaval, swordsmiths across Japan mass-produced large, practical swords to meet the demands of the battlefield. Ōdachi and nodachi with blade lengths exceeding 3 shaku (approx. 90 cm) reflect how fierce the battles of this era were. In addition to the major production centers of Bizen, Yamashiro, and Yamato, the Sōshū tradition (the lineage of Masamune) spread to swordsmiths nationwide, and eclectic styles such as Sōden Bizen emerged in Bizen. In the Muromachi period after reunification (from the Ōei era onward), as warfare subsided, sword forms changed again. A return began from large ōdachi toward medium-sized tachi and uchigatana that were easier to carry, and swords regained value as works of art and ceremonial objects alongside their practical use as weapons.

Higashiyama Gomotsu and Ashikaga Yoshimitsu — Establishing the Culture of Sword Appreciation

Backed by his great power, Ashikaga Yoshimitsu launched the Japan–Ming trade with China (Ming) and accumulated enormous wealth. This wealth was also invested in cultural enterprises, and alongside Noh, renga, ink painting, and the tea ceremony, Yoshimitsu refined the culture of sword appreciation. The swords and art objects Yoshimitsu collected were the forerunners of the Higashiyama Gomotsu (Higashiyama Collection) and symbolized the cultural authority of the later Ashikaga shogunal house. Yoshimitsu actively used swords not merely as arms but as tools of gift-giving, diplomacy, and the display of authority. Japanese swords also served as important gifts in the envoy to Ming (1401), and later in the kangō trade, Japanese swords became a major export. The 'Yoshimitsu era' after the Reunification of the Northern and Southern Courts was an important turning point in which swords shed their role as weapons and became art objects and cultural properties.

Historical Significance of the Reunification of the Northern and Southern Courts — The Spirit of the Age Embodied by Japanese Swords

The 56 years of upheaval in the Nanboku-chō period brought the most dramatic changes to the forms, techniques, and spiritual culture of Japanese swords. The rise of the ōdachi, the nationwide spread of the Sōshū tradition, the establishment of the mass-production system in Bizen, and the flourishing of the culture of appreciation after the Reunification of the Northern and Southern Courts form a sequence that overlaps with the process by which Japanese swords rose beyond being mere weapons to become special objects with composite values: the 'soul of the warrior,' 'works of art,' and 'sacred treasures.' With the Meitoku Peace Accord bringing an end to the upheaval, and as Yoshimitsu's Muromachi shogunate entered a period of stability, the cultural practices of sword appreciation, sword gifting, and sword dedication became established as formal etiquette in warrior society. The direct origins of today's culture of sword authentication, preservation, and display lie in the cultural soil formed in the Muromachi period after the Reunification of the Northern and Southern Courts. The political event of the reunification can be read in the history of swords as a 'turning point from the age of weapons to the age of culture,' and it is an important historical juncture.

Later Southern Court and Sword Succession — The Last Struggle Over the Three Sacred Treasures

Even after the Meitoku Peace Accord, resistance by descendants of the Southern line continued sporadically. The 'Later Southern Court' (Gonanchō), led by the descendants of Emperor Go-Kameyama, based itself around Yoshino and Mount Kōya and asserted its legitimacy from the Ōei era onward. In Kakitsu 3 (1443), the 'Kinketsu Incident' occurred, in which forces of the Later Southern Court forced their way into the imperial palace and seized the sword and the jewel from among the Three Sacred Treasures. The Sacred Sword was soon recovered by the shogunate's side, but the Sacred Jewel (shinji) remained with the Later Southern Court and was recaptured in Chōroku 2 (1458) by former retainers of the Akamatsu clan. This incident shows that the Three Sacred Treasures held a special spiritual value as 'sacred blades' connected to Japanese swords, going beyond mere political symbols. The idea that swords are both weapons and works of art and also 'sacred treasures' was carved more deeply into the Japanese spirit through the Nanboku-chō upheaval and the resistance of the Later Southern Court that followed. The Meitoku Peace Accord, which achieved reunification of the Northern and Southern Courts, was a provisional settlement of this 'struggle over the sacred treasures,' but the resistance of the Later Southern Court that followed meant it was not a complete conclusion. From the perspective of sword history, the resistance of the Later Southern Court that continued after reunification is evidence that the 'symbolic and sacred value' of Japanese swords retained powerful centripetal force even in the political context. The movements of the Later Southern Court, represented by the Kinketsu Incident (1443), are valuable historical testimony showing that the Japanese spiritual culture in which swords and sacred treasures were unified continued to function as a living political reality even in the Muromachi period.

Kaō (Signature Monograms) of the Muromachi Period and Swords — The Diplomatic Function of Swords in the Yoshimitsu Period

From the 1390s, when Ashikaga Yoshimitsu achieved the Reunification of the Northern and Southern Courts, until his death in Ōei 15 (1408), Japanese swords played an important diplomatic role in relations with Ming China. Yoshimitsu sent an envoy to Ming in Ōei 8 (1401). The following year, he was invested by the Jianwen Emperor as 'King of Japan,' and from Ōei 11 (1404), the Japan–Ming trade was conducted using kangō tallies. Japanese swords were used as one of the main gifts in this envoy and were highly valued at the Ming court. Chinese records praise the sharpness and beauty of the Japanese swords (wodao), and the international reputation of Japanese swords was strengthened through Yoshimitsu's diplomacy in this period. It was also at this time that the surplus of Japanese swords mass-produced during the Nanboku-chō upheaval began to circulate in the international market as diplomatic gifts and trade goods. Stability within the country brought about by the Meitoku Peace Accord, and the Japan–Ming trade established under Yoshimitsu's strong leadership, became an important opportunity to position Japanese swords as a 'world commodity' in the international market. It is interesting, as a viewpoint for understanding this era from many angles, that a domestic political event, the Reunification of the Northern and Southern Courts, contributed to sword history in the unexpected form of the international evaluation and circulation of Japanese swords.