Ashikaga Tadayoshi

Ashikaga Tadayoshi (1306-1352) was the full younger brother of Ashikaga Takauji, an important figure who handled shogunate administration alongside his elder brother Takauji in the founding period of the Muromachi Shogunate. While assisting the militarily accomplished Takauji, he led the administration and legal system development of the shogunate, supporting the Muromachi Shogunate through the turmoil of the Northern and Southern Courts period. However, the conflict between Tadayoshi and Takauji's administrative officer Kō no Moronao developed into a large-scale internal struggle within the shogunate (the "Kannō Disturbance"), and his eventful life embodies the complex political situation of the Northern and Southern Courts era.

Tadayoshi devoted himself to both literary and martial arts from youth and participated in his brother Takauji's movement to overthrow the Kamakura Shogunate. During the Kemmu Restoration after the shogunate's fall, he initially sided with Emperor Go-Daigo, but followed Takauji when he rebelled against the new government. After the Battle of Minatogawa (1336) and the establishment of the Muromachi Shogunate, a "dual government" was established in which Takauji handled warrior affairs while Tadayoshi managed general administration and judicial matters. Under this system, Tadayoshi worked to develop shogunate law, protect temples and shrines, and promote culture, contributing to the stability of shogunate administration.

However, conflict within the shogunate intensified between the faction of Takauji's officer Kō no Moronao (the martial faction) and Tadayoshi's faction (the civilian governance faction). In 1349, Tadayoshi faced a crisis as Moronao sought to exclude him from administration; though he attempted to resolve the situation by taking Buddhist vows, he ultimately succeeded in killing the Kō brothers, Moronao and Moroyasu (the Kannō Disturbance). Through this process he followed a complex course of making peace with the Southern Court and opposing Takauji, ultimately surrendering to Takauji. In 1352, Tadayoshi died suddenly in Kamakura. There are suspicions of poisoning, and the true circumstances of his death remain shrouded in mystery.

Ashikaga Tadayoshi excelled more as an administrator and legislator than as a warrior, and is said to have been deeply involved in the formulation of the "Kemmu Shikimoku" (the Muromachi Shogunate's governing principles). His achievements in establishing the shogunate's governance foundation during the turmoil of the Northern and Southern Courts era were significant, and he is evaluated as the person who laid the foundations for the legal system and culture of the Muromachi period. In relation to swords, Tadayoshi was also a warrior who participated in major battles himself, and records remain of him wearing famous swords as a member of the Ashikaga clan.