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. 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 the 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. 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 and The Go-Hōjō clan then sent Hōjō Ujinobu as representative, while the Tokugawa sent Ii Naomasa as representative for the preliminary meetings. Furthermore, In October, representatives from the Oda clan such as
Oda Nobukatsu,
Oda Nobutaka, and Toyotomi mediated the negotiation until the truce officially concluded.
Suwa taisha was designated as the chief Shinto shrine (
ichinomiya) for the province. In 1871, during the
Meiji period, with the
abolition of the han system and the establishment of
prefectures (
Haihan Chiken) after the
Meiji Restoration, Shinano Province's ex-domains/1871 prefectures and ex-shogunate territories/1868 prefectures (mainly
Ina [merger of several shogunate demesne administrations with parts of
Matsumoto],
Okutono,
Iwamurada,
Komoro,
Ueda,
Matsushiro,
Suzaka,
Iiyama,
Suwa/Takashima,
Takatō,
Iida,
Matsumoto) and
Takayama/Hida which covered
Hida Province were administratively merged into Nagano (initially
Nakano Prefecture in 1870) and
Chikuma prefectures. The seat of the prefectural government of Nakano was Nakano town from
Takai District (became
Nakano City in 1954), Nagano's prefectural capital was Nagano town in
Minochi District (→
Nagano City in 1897), and Chikuma's capital was Matsumoto town,
Chikuma district (
Matsumoto City from 1907). In the second wave of prefectural mergers in 1875/76, Chikuma was split again: the Western part covering Hida Province was merged into Gifu, and the Eastern part in Shinano became part of Nagano. Since that time, Nagano is essentially contiguous to Shinano. ==Historical districts==