was a minor fudai feudal domain under the Tokugawa shogunate of Edo period Japan. based in southern Mutsu Province in what is now part of modern-day Iwaki, Fukushima. It was ruled for the entirety of its history by the Naità  clan. The domain was initially known as
In 1622, the 70,000 koku Iwakitaira Domain was assigned to Naità  Masanaga. In 1670, his son and 2nd daimyà  Naità  Tadaoki transferred 10,000 koku of newly developed rice lands to his younger son, Tà Âyama Masasuke, creating a subsidiary domain based at Yumoto jin'ya. In 1676, Masasuke moved the location of his jin'ya from Yumoto to nearby Yunagaya and laid out the foundations of his castle town. In 1680, as a reward to helping suppress a rebellion by Naità  Tadakatsu, the daimyà  of Toba Domain, he was awarded an additional 2000 koku estate in Tamba Province. He served as castellan of Osaka Castle in 1687, and was rewarded with another 3000 koku in Kawachi Province, bringing the kokudaka of the domain to 15,000 koku.
Although the Naità  clan in Iwakidaira were transferred to Nobeoka Domain in distant Kyushu by the shogunate due to mismanagement in 1747, the Naità  of Yunagaya remained until the end of the Tokugawa shogunate despite a propensity of its rulers to die young and without heir. The 4th daimyà Â, Naità  Masaatsu, codified the domainâÂÂs laws, and the 10th daimyà Â, Naità  Masatami established a domain academy. In 1855, significant coal deposits were found within the domain.
At the time of the Meiji restoration, the 13th daimyà Â, Naità  Masayasu was still an infant. The domain joined the à Âuetsu Reppan Dà Âmei during the Boshin War, but was captured by Imperial forces without a struggle. The domain was reduced by only 1000 koku, and Masayasu was forced to abdicate in favor of the 14th and last daimyà Â, Naità  Masanori in 1869. He remained as imperial governor until the abolition of the han system in July 1871.
As with most domains in the han system, Yunagaya Domain consisted of several discontinuous territories calculated to provide the assigned kokudaka, based on periodic cadastral surveys and projected agricultural yields.
was the 1st daimyà  of Yunagaya Domain. He was the 3rd son of Naito Tadaoki, the 2nd daimyà  of Iwakitaira Domain. In December 1670, when his father retired from public life, he separated out a 10,000 koku holding and authorized Masasuke to set up his own household as daimyà  of . In November 1676, he relocated his seat to Yunagaya, and the domain was renamed accordingly. Masasuke built Yunagaya Castle and the surrounding castle town. In 1680, an incident occurred at Zà Âjà Â-ji in Edo, wherein Naità  Tadakatsu (daimyà  of Toba Domain) attacked and killed Nagai Nonage (daimyà  of Miyazu Domain). Naità  Tadakatsu was forced to commit seppuku, and Masasuke inherited 2000 koku of his holdings in Tamba Province. In 1687, Masasuke was selected to serve in the guards at Osaka Castle, and his revenues were increased by another 3000 koku. His courtesy title was Tonomo-no-kami, and his Court rank was Junior Fifth Rank, Lower Grade. He died while in service at Osaka and his grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura. Masasuke was married to a daughter of Sanada Nobuyuki, but had no children.
was the 2nd daimyà  of Yunagaya Domain. He was the 2nd son of Hori Naoyuki, the son of Hori Naokage, daimyà  of Kariya Domain and was adopted by Tà Âyama Massuke to be his heir in 1690. He became daimyà  in 1694. His courtesy title was Naizen-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. However, Masanori never married and died childless at the age of 30 in 1703. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 3rd daimyà  of Yunagaya Domain. He was the 2nd son of Hijikata Katsuyoshi, a 200 koku hatamoto; however, his great-grandmother was the daughter of Naità  Masanaga and his wife was a daughter of Naità  Tadaoki. He was posthumously adopted as heir to Masanori in 1703, and died in 1722 at the age of 38. His courtesy title was Tonomo-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 4th daimyà  of Yunagaya Domain. He was the son of Naità  Masasada and became daimyà  at the age of two on his fatherâÂÂs death in 1722. He was received in formal audience by Shà Âgun Tokugawa Ieshige in 1755. His wife was a daughter of Kuroda Naokuni, daimyà  of Shimodate Domain. His courtesy title was Harima-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. He died in 1741 in Yunagaya shortly after returning from sankin kà Âtai in Edo at the age of 31. His grave is at the temple of Ryà «shà Â-ji in Iwaki, Fukushima.
A highly fictionalized Naità  Masaatsu was the main character in the 2014 jidaigeki comedy film Samurai Hustle, where he was played by actor Kuranosuke Sasaki.
was the 5th daimyà  of Yunagaya Domain. He was the son of Naità  Masaatsu and became daimyà  of his fatherâÂÂs death in 1741. He was received in formal audience by Shà Âgun Tokugawa Yoshimune. His courtesy title was Harima-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. He turned the domain over to his adopted son, Naità  Sadayoshi in 1761 for unknown reasons and went into retirement. He died in 1769, and his grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura, although some records indicate that he may have lived to 1811. He never married.
was the 6th daimyà  of Yunagaya Domain. He was the sixth son of Tokugawa Munenao of Kii Domain and his wife was the daughter of Hijikata Katsumasa, daimyà  of Komono Domain. He became daimyà  in 1761 after his adopted father was received in formal audience by Shà Âgun Tokugawa Ieharu and unexpectedly went into retirement immediately thereafter. He had four sons and one daughter. He died in 1778 at the age of 33, and his grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 7th daimyà  of Yunagaya Domain. He was the second son of Naità  Sadayoshi. He became daimyà  in 1778 on his fatherâÂÂs death. During his tenure, the domain suffered greatly from the Great Tenmei famine on 1782. He died in 1787 at the age of 18, and his grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 8th daimyà  of Yunagaya Domain. He was the younger brother of Naità  Masahiro and the fourth son of Naità  Sadayoshi. He became daimyà  in 1787 on the unexpected death of his brother. He was married to the daughter of Matsudaira Yorikata of Saijà  Domain. He was received in formal audience by Shà Âgun Tokugawa Ienari in 1790. His courtesy title was Tonomo-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. He died in 1799 at the age of 27 and without heir, and his grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 9th daimyà  of Yunagaya Domain. He was the 10th son of Mizuno Tadakane, daimyà  of Karatsu Domain, and was posthumously adopted in 1799 to be heir of Naità  Masayuki. He married the daughter of Naità  Masatame, the eldest son of Naità  Sadayoshi, who had died young. His courtesy title was Harima-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. During his tenure, the domain suffered from floods in 1821 followed by drought in 1821. He retired in 1824 and died in 1836 at age 52. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 10th daimyà  of Yunagaya Domain. He was the 5th son of Sakai Tadaari, daimyà  of Shà Ânai Domain, and was adopted in 1824 to be heir of Naità  Masaakira when the latter unexpectedly decided to retire. He married the daughter of Naità  Masaakira. he built a han school modelled after the Chidà Âkan in his native Dewa Province, at which he also acted as an instructor. His courtesy title was Inaba-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. He died in 1855 at age 50. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 11th daimyà  of Yunagaya Domain. He was the 3rd son of Matsudaira Mitsutsune, daimyà  of Matsumoto Domain, and was adopted in 1855 to be heir of Naità  Masatami, who had only four daughters. His courtesy title was Harima-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. However, he died only 4 years later in 1859 at the age of 24. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 12th daimyà  of Yunagaya Domain. He was the eldest son of Naità  Masashige, daimyà  of Komoro Domain and was adopted in 1859 to be the posthumous heir to Naità  Masatsune. However, he died only 4 years later in 1863 at the age of 21. His courtesy title was Inaba-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 13th daimyà  of Yunagaya Domain. He was the posthumous third son of Naità  Masatsune, the 11th daimyà  of Yunagaya and was adopted by Naito Masatoshi as his heir. He became daimyà  on MasatoshiâÂÂs death in 1863. His courtesy title was Inaba-no-kami, and his court rank was Junior Fifth Rank, Lower Grade. In early 1868, the domain received orders from the new Meiji government to participate in the Battle of Aizu during the Boshin War; however, one month later, the domain joined the pro-Tokugawa à Âuetsu Reppan Dà Âmei instead. Masayasu was only 12 years old at the time. Meiji government forces occupied Yunagaya one month later, and Masayasu fled to Sendai. He surrendered to the Meiji government that autumn and was ordered to Tokyo, where he was placed under house arrest. He was forced to retire in favor of his adopted son, Masanori, and the domain was punished by the government by a reduction in its kokudaka of 1000 koku. He died in 1911 at the age of 55. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.
was the 14th and final daimyà  of Yunagaya Domain. He born the son of the kuge Oinomikado Ietaka. The Meiji government ordered him to succeed Naità  Masaysu, then under house arrest in Tokyo for the domainâÂÂs participation in the pro-Tokugawa à Âuetsu Reppan Dà Âmei in 1869. Later that year, when the position of daimyà  was abolished, he became imperial governor, and continued to rule Yunagaya even after the abolition of the han system in 1871. He retired in December 1881 and died in 1919 at age 72. His grave is at the Naità  Cemetery at Kà Âmyà Â-ji in Kamakura.