Mizuno Tadakuni (水野忠邦)

Tadakuni MIZUNO was a daimyo (Japanese feudal lord) and roju (senior councilor of the Tokugawa shogunate) who lived during the Edo Period.

From birth to a lord of the Karatsu and Hamamatsu Domains

Tadakuni was born as the second son to the third lord of the Karatsu Domain, Tadaaki MIZUNO, on June 23, 1794.

As the eldest brother, Fusamaru, died young, Tadakuni became an heir of the Karatsu Domain in 1805 and had an audience with the 11th Seii Taishogun (commander-in-chief of the expeditionary force against the barbarians), Ienari TOKUGAWA, and his heir, Ieyoshi TOKUGAWA in 1807. Tadakuni was appointed as shikibu shoyu (Junior Assistant of the Ministry of Ceremonial) and was conferred the rank of Jugoinoge (Junior Fifth Rank, Lower Grade).

When Tadakuni's father, Tadaaki, retired in 1812, Tadakuni succeeded the reigns of the family. He assumed the position of sojaban (an official in charge of the ceremonies) in 1816. As soon as Tadakuni, who sought further promotions beyond sojaban, recognized that the Karatsu Domain, which was assigned to defend Nagasaki, impeded such promotions, he, against his vassals' advice, requested bakufu to change his domain from the Karatsu Domain with 253,000 koku (70,334 cubic meters) to the Hamamatsu Domain with 153,000 koku (42,534 cubic meters), and finally realized it in September, 1817. During this domain transfer, the chief retainer of the Mizuno clan, Yoshikado NIHONMATSU, died in remonstration. The people in the domain held a grudge against Tadakuni well into later years, because a part of the Karatsu Domain was taken away by bakufu as a shogunal demesne, and they suspected that this was used as a bribe to realize the domain transfer, and they also suffered a harsh tax collection in the demesne. In recognition of his service in achieving the domain transfer, Tadakuni was also appointed as jisha bugyo (magistrate of temples and shrines) in the same year.

Since then, Tadakuni had made remarkable progress under the shogun, Ienari, and got a promotion to Osaka jodai (the keeper of Osaka Castle) and was conferred the rank of Jushiinoge (Junior Forth Rank, Lower Grade) in 1825. He was promoted again to Kyoto shoshidai (The Kyoto deputy) and was conferred the title of jiju (Imperial Household Agency staff) and Echizen no kami (Governor of Echizen Province) in 1826, followed by a further promotion in 1828 to roju (member of shogun's council of elders) of Nishinomaru Goten Palace to support Ieyoshi TOKUGAWA, a shogunal heir.

To replace Tadaakira MIZUNO, who died of disease in 1834, Tadakuni was appointed as roju of Honmaru Palace, and also promoted to roju shuza (the head of roju) in 1839 after additionally held the post of katte goyo-gakari (director of finance) in 1837.

Tempo Reforms

While foreign ships threatened the Japanese coastal defense by appearing in waters around Japan, it is believed that Tadakuni was feeling a strong sense of danger against Edo bakufu that could not find any solution for loose management of finance which suffered a significant income decline in annual rice tax during the Ogosho (retired Shogun) period. However, while Ienari was alive, the Ienari's close advisers including Tadaatsu MIZUNO (hatamoto or bannerman), Tadafusa HAYASHI and Mochinaru MINOBE (the three were comprehensively called Tempo no san-Neijin) wielded dictatorial power in bakufu, which prevented Tadakuni from launching any reform.

When Ieyoshi TOKUGAWA became the 12th shogun in April 1837 and Ienari TOKUGAWA, Ogosho, died in leap January 1841, Tadakuni first dismissed close advisors of Ienari and newly employed Kagemoto TOYAMA, Sadanori YABE, Masanari OKAMOTO, Yozo TORII, Hironao SHIBUKAWA and Sanemon GOTO to initiate the Tempo Reforms. During the Tempo Reforms, a memorandum was issued, which says 'strive hard to revive the politics of Kyoho and Kansei eras,' and so many laws were enacted that it was called 'Horei Uka' (laws fall like a rain).

In reflection of a massive influx of peasants from farming villages to Edo, Tadakuni issued the 'Hito gaeshi-rei' (a law to return peasants to their villages) to reconstruct faming villages, and also banned luxury goods and reinforced tighter discipline on public morals in order to rehabilitate the city which was loosened up during the Ogosho Period. Also, he dissolved merchant guilds as a part of the low-price policy, as he placed a blame on them for rising goods prices, but he minted low-quality coins to compensate the finance shortage of bakufu at the same time, which brought about an outcome completely opposite to a price reduction. Also, a strong opposition from daimyos and hatamotos to Agechi-rei (confiscation command of territory) was arisen when Tadakuni tried to force it through in September 1843, and treachery by his trusted retainer, Yozo TORII, was revealed, who switched sides and gave classified documents to Toshitsura DOI, anti-Agechi-rei roju, both of which caused the dismissal of Tadakuni from roju on leap September 13 and the ultimate downfall of Tadakuni later.

Downfall and reappointment as roju

It is believed that the reform conducted by Tadakuni was so radical that it caused resentment among common people of Edo who ended up raiding his residence upon his discharge from roju.

However, when the main ward of Edo Castle was burned down in May 1844, a new roju shuza, Toshitsura DOI, could not gather enough money for the reconstruction of the castle, and this displeased Ieyoshi and led him reappoint Tadakuni as roju shuza on June 21, under the excuse of complicated foreign issues. However, it is said that Tadakuni was not what he had used to be anymore and often seemed distracted in his office. On the other hand, Tadakuni avenged on Toshitsura DOI and Yozo TORII who betrayed him during the Tempo Reforms.

However, amid the strong opposition to Tadakuni's reappointment from roju, Masahiro ABE and the former roju, Toshitsura DOI, Tadakuni was suspected of taking a bribe from Yozo TORII and Sanemon GOTO during the Tempo Reforms, which worked as a negative factor to Tadakuni and deprived him of 10,000 koku (2,780 cubic meters) from his additional territory and another 10,000 koku from his original territory as an punitive measure in September 1845, and his territory was reduced to 50,000 koku (13,900 cubic meters). Tadakuni was placed under house arrest and ordered to retire,then later transferred to the Yamagata Domain of Dewa Province, after Tadakiyo MIZUNO, his eldest son, was allowed to succeed the family reigns.

Tadakuni died on February 10, 1851. His suspension order was lifted five days after his death.

Record of offices and ranks held

Date according to old lunar calendar

1802: He called himself, Otogoro.

September 1805: His imina (personal name) was changed to Tadakuni.


September 7: He celebrated genpuku (celebration to reach the manhood).

November 7: He was conferred a rank of Jugoinoge and was appointed as shikibu shoyu.

August 1812: He succeeded the reigns of the family. He inherited the Karatsu Domain (60,000 koku or 16,680 cubic meters) of Hizen Province and was appointed as Izumi no kami Guard.

November 12, 1815: He was promoted to sojaban.


August: He changed his territory to Hamamatsu (60,000 koku) of Totoumi Province.

September 10: He was additionally appointed as jisha bugyo. He was appointed as sakone no shogen (Lieutenant of the Left Division of Inner Palace Guards).

May 15, 1825: He was promoted to Keeper of Osaka-jo Castle. He was conferred a rank of Jushiinoge.


November 23: He was promoted to Kyoto shoshidai. He additionally served as jiju.

December: He was transferred to Echizen no kami.

November 23, 1828: He was promoted to Nishinomaru roju.

March 1, 1834: He was appointed as roju (Honmaru roju).

March 27, 1837: He was additionally appointed as katte gakari.

December 2, 1839: He was promoted to roju shuza.


March: He issued 'Hito gaeshi-rei'.

June 1: He issued 'Agechi-rei'.

Leap September 7: He withdrew 'Agechi-rei'.

Leap September 13: He was dismissed from roju. He was suspended from a job. He served as karinomatsume (feudal lord that Karino-ma room in Edo-jo castle was set as his station).

June 21, 1844: He was reappointed as roju. He was promoted to roju shuza.


February 22: He retired from roju.

September 2: He retired and was put under house arrest. His 10,000 koku was confiscated. He was transferred to Yamagata (50,000 koku) of Dewa Province.

Vassals of Tadakuni MIZUNO

The following is the list of major vassals of Tadakuni served in 1817 and 1829.

In 1817

karo (chief retainers)


jodai (castle keeper)

Shichiro NIHONMATSU (doubled as toshiyori [senior councilor])

toshiyori (close associates of Shogun)

Kichiemon YAMANAKA, Magobei OKUBO, Hikoemon IWASAKI, 丹氏 HAIGO, Heisuke TAKUSHOKU, Koasaburo MIZUNO, Kazusuke NIHONMATSU

yojin (lord chamberlain)

Monemon TSUDA, Shirozaburo OKABE

gojoshi (keeper of Edo-jo Castle)

Hachiroemon INOUE

soeyaku (assistant)

Tsunezo SATO

In 1829


Genzaemon HAIGO, Kametaro MIZUNO


Hikozaemon IWASAKI, Heisuke TAKUSHOKU, Koazaburo MIZUNO, Uchizo HAIGO, Monzaemon TSUDA, Tenbei AKIMOTO

Yonin (who conducts gengeral affairs for his lord)
Shirosaburo OKABE, 屯 OKUBO (doubled as sobayonin), Sakuemon INOUE (doubled as Kojonin), Shima YAMANAKA

Koyonin (who conducts affairs related to the bakufu)
Ikuemon MAKITA, Shinbei SATO