In 713, the road that traverses Mino and Shinano provinces was widened to accommodate increasing numbers of travelers through the Kiso District of modern Nagano Prefecture.[2]
In the Sengoku period, Shinano Province was often split among fiefs and castle towns developed, including Komoro, Ina, and Ueda. Shinano was one of the major centers of Takeda Shingen's power during his wars with Uesugi Kenshin and others.
During the Azuchi–Momoyama period, after Nobunaga's assassination at Honnō-ji Incident, the province was contested between Tokugawa Ieyasu and the Go-Hōjō clan based in Odawara castle. The Tokugawa clan, The Uesugi clan and the Hōjō clan each aspired to seize the vast area in Shinano Province, Ueno region, and Kai Province, which ruled by the remnants of the many small clans formerly serving Takeda clan. Following of disorder post death of Nobunaga, at the same time with Ieyasu departure an army of 8,000 soldiers to those disputed region. This caused the triangle conflict between those three factions in the event which dubbed by historians as Tenshō-Jingo War broke out.[3][a] As the war turned in favor of Tokugawa clan, combined with the defection of Sanada Masayuki to the Tokugawa faction, the Hōjō clan now negotiate truce with Ieyasu[6] and The Go-Hōjō clan then sent Hōjō Ujinobu as representative, while the Tokugawa sent Ii Naomasa as representative for the preliminary meetings.[7][8] Furthermore, In October, representatives from the Oda clan such as Oda Nobukatsu, Oda Nobutaka, and Toyotomi mediated the negotiation until the truce officially concluded.[9]
^The name of『Tenshō-Jingo War』was coined by Tashiro Takashi in 1980.[4] Furthermore, is also a theory that from the perspective that local powers which continued to fight over the possession of the Oda clan's leftover territories, there is evidence that Tokugawa Ieyasu's transfer to the Kantō region region following the fall of the Hōjō clan in 1590 and the placement of Toyotomi-line daimyo, until transfer of Uesugi Kagekatsu to Aizu, where the local daimyo were separated from their former territory and the establishment of control by the Azuchi–Momoyama period, was considered to be the extension of this conflict.[5]
^Masaru Hirayama (2016). "天正壬午の乱【増補改訂版】─本能寺の変と東国戦国史" [Tensho Migo Rebellion [revised and enlarged edition] - Honnoji Incident and the history of the Sengoku period in the Togoku region] (in Japanese). Ebisukosyo. Retrieved 17 May 2024.
^Okamoto Ryoichi (岡本亮一) (1982). 日本城郭史研究叢書 第8巻 大坂城の諸研究 [Japanese Castle History Research Series Vol. 8 Various Studies on Osaka Castle] (in Japanese). 名著出版. pp. 412–413. ISBN4404010362. Retrieved 6 June 2024.
^Aida Nirō (1976). 日本古文書学の諸問題 (in Japanese). 名著出版. Retrieved 15 May 2024.
^千葉琢穂 (1989). 藤原氏族系図6 [Fujiwara clan genealogy 6]. 展望社. p. 227. Retrieved 15 May 2024.
^Kazuhiro Marushima (丸島和洋) (2015). "北条・徳川間外交の意思伝達構造" [The structure of communication in diplomacy between the Hojo and Tokugawa]. 国文学研究資料館紀要. 11 (11). 国文学研究資料館: 33–52. doi:10.24619/00001469. ISSN1880-2249.
