Takeda Shingen’s military and political skills, which enabled him to rule over Kai Province, modern-day Yamanashi Prefecture, and much of the central part of the Japanese archipelago, struck fear into the hearts of other feudal lords of his time. However, his powers were not the result of his abilities alone. The Takeda clan was able to expand its influence because of the support of many capable vassals who understood Shingen’s military and political strategies and were able to put them into action.

During Japan’s Warring States period, the inheritance of clan leadership was usually the right of the first-born son. Therefore, many families chose their heirs regardless of their abilities. Shingen, however, promoted second and third sons who would normally not be eligible. He gave the most talented the chance to inherit the family’s title and to play active roles. Furthermore, Shingen promoted non-samurai such as farmers, without regard to their rank or status, and trained them from an early age by keeping them close to him as his lieutenants. Yamagata Masakage and Naitō Masahide, who supported the Takeda army and are known as two of the Big Four Takeda Generals, were second sons of their own families, while Baba Nobuharu was from a small powerful family guarding the border, and Kasuga Toratsuna was from a farmer’s family. Others, such as Yamamoto Kansuke, were actively promoted as long as they were excellent, even if they came from other provinces.

Before the Takeda clan rose to become a formidable force beyond Kai Province, it’s members were constantly embroiled in disputes over succession and power, and many of Shingen’s relatives perished in the process of the unification of the province under Shingen’s father, Nobutora. As a result, by the time Shingen became the feudal lord of Kai, there were few reliable relatives left, except for Shingen’s brothers and their close relatives. Furthermore, some long-standing vassals refused to follow Shingen’s directives. Yet, Shingen was successful in selecting capable vassals who in turn supported the Takeda clan’s rapid rise.

The organization of Shingen’s vassals is unclear due to a lack of historical records from the time, but according to the Kōyō Gunkan, a record of the military exploits of the Takeda clan, it was composed of three groups: the Goichimonshū, who were related to Shingen by blood; the Fudai Karōshū, who had served the Takeda clan for several generations; and the Senpōshū, who followed the Takeda clan as it expanded its territory.

The forces led by Shingen were feared by the rest of Japan and won a great victory at the Battle of Mikatagahara against Tokugawa Ieyasu, which was Shingen’s last major battle. After Shingen’s death, Ieyasu, who ultimately destroyed the Takeda clan, inherited the vassals and military system bequeathed by Shingen and eventually established the Tokugawa shogunate in Edo, modern-day Tōkyō, to rule the entire country for more than 260 years. During this period, known as the Edo period (1603-1868), Shingen and his vassals were revered for their victory over Ieyasu and the vassals became known as the “Twenty-three Generals of Takeda Shingen.” Thus, paintings of Takeda and his generals were very popular, and many survive to this day.