was a feudal domain under the Tokugawa shogunate of Edo period Japan. It was located in northern Shinano Province, Honshū. The domain was centered at Iiyama Castle, located in what is now part of the city of Iiyama in Nagano Prefecture.
History
In 1603, when Matsudaira Tadateru was awarded Kawanakajima Domain, the area around Iiyama was assigned to his retainer, Minagawa Hiroteru as a 40,000 koku holding. This marked the start of Iiyama Domain. however, after Matsudaira Tadateru fell from favour with shōgun Tokugawa Ieyasu and was dispossessed, Minagawa Hiroteru suffered a similar fate and was demoted to the 10,000 koku Hitachi-Fuchū Domain. He was replaced by Hori Naoteru from a cadet branch of the Hori clan of Echigo Province. Hori Naoteru took active steps in flood control and the opening of new rice lands to improve the domain. However, he was transferred to Nagaoka Domain in 1616. Iiyama then went to Sakuma Yasumasa, the son of one of Oda Nobunaga's famed generals, Sakuma Morimasa. The Sakuma clan ruled for three generations until the line died out without an heir in 1638. Iiyama Domain was then assigned to a branch of the Matsudaira clan, formerly from Kakegawa Domain. The Matsudaira ruled for two generations, and returned to Kakegawa in 1706. Iiyama was then assigned to Nagai Naohiro, formerly lord of Akō Domain immediately after the famed Forty-seven rōnin incident. He remained only until 1711 when he was replaced by Toyama Yoshihide, who also stayed for only six years before he too was transferred elsewhere.
In 1717, Iiyama Domain was awarded to a cadet branch of the Honda clan, under whose control it remained until the Meiji Restoration. During the Boshin War, the domain was invaded by pro-Tokugawa forces from Takada Domain, who set fire to the castle town. The domain subsequently supported the imperial armies at the Battle of Hokuetsu and Battle of Aizu. In July 1871, with the abolition of the han system, Iiyama Domain briefly became Iiyama Prefecture, and was merged into the newly created Nagano Prefecture.
Bakumatsu period holdings
As with most domains in the han system, Iiyama Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields. Shinano Province 58 villages in Minochi District
List of Daimyō
Honda Sukeyoshi
was a daimyō in the early Edo period Tokugawa shogunate of Japan. He was the 2nd Honda daimyō of Murayama Domain in Dewa Province, daimyō of Itoigawa Domain in Echigo province and 1st Honda daimyō of Iiyama Domain in Shinano Province. Sukeyoshi was born in Edo as the younger son of a 4560 koku hatamoto of Okazaki Domain in Tōtōmi province. He received a 300 koku stipend on the death of his father in 1669. In 1688, he was adopted as the heir to Honda Toshinaga of Murayama Domain and was received in formal audience by Shōgun Tokugawa Tsunayoshi. He became daimyō of Murayama (10,000 koku) on the death of his adopted father in 1693. In 1699, the Tokugawa shogunate ordered his transfer to Itoigawa, with the same kokudaka, and he was given the courtesy title of Wakasa-no-kami. In 1717, he was transferred to Iiyama (12,000 koku), where his descendants resided to the Meiji Restoration. He also changed his name from Toshihisa (利久) to Sukeyoshi (助芳). However, due to repeated flooding of the Chikuma River and the mountainous terrain of his new holding, he found that the actual financial situation in Iiyama was much worse than its kokudaka reflected, and from the start the domain suffered from financial problems. His wife was a daughter of Matsudaira Sadashige of Kuwana Domain. He died in 1727 and his grave is at the temple of Kyōzen-ji in Roppongi, Tokyo.
Honda Yasuakira
was the 2nd Honda daimyō of Iiyama Domain. Yasuakira was born in Edo and was the third son of Honda Sukeyoshi. As his two elder brothers died in childhood, he became daimyō on the death of his father in 1725. However, in 1730 en route to visit his holdings in Iiyama, he fell ill and died soon after reaching Iiyama Castle at the age of 22. His grave is at the temple of Chuon-ji in Iiyama.
Honda Sukemochi
was the 3rd Honda daimyō of Iiyama Domain. Sukemochi was the fourth son of Honda Sukeyoshi, and was posthumously adopted as heir on his brother Yasuakira's sudden death without heir in 1730. However, he was in poor health from infancy, and he also died without male heir in 1737 at the age of 24. His wife was a daughter of Suwa Tadatora of Suwa Domain. His grave is at the temple of Kyōzen-ji in Roppongi, Tokyo.