This came in the wake of the signing of the Harris Treaty on 1858/6/19, a deeply unpopular move among many prominent figures in the realm not only in terms of disagreements as to what the shogunate's foreign policy approaches or stances should be, but also because the treaty was signed without imperial approval. Further, many of those who opposed the signing of the treaty also actively supported Tokugawa Yoshinobu rather than Tokugawa Yoshitomi (Iemochi) as the shogunal successor, plotting behind the back of the shogunate to gather support among court nobles, daimyo, and others, as well as imperial orders explicitly backing Yoshinobu and calling for the negation of the treaty. Yoshitomi was officially named shogunal heir on 1858/6/25.
The purges began as early as 1858/7/5, with Tokugawa Nariaki (former lord of Mito han) being sentenced to house arrest, and Tokugawa Yoshikumi (lord of Nagoya han) and Matsudaira Yoshinaga (lord of Fukui han) being forced into retirement and house arrest. The shogunate designated Matsudaira Yoshichika (lord of Takasu han) to become the new lord of Nagoya, and Matsudaira Naokiyo (lord of Itoigawa han) to become the new lord of Fukui. Iesada died the following day, on 7/6. Formal visits to Edo castle by Tokugawa Yoshinobu (the rival claimant for the position of shogunal heir), as well as lord of Mito han Tokugawa Yoshiatsu, were briefly suspended.
Wakadoshiyori Hongô Yasukata, Sobashû Ishikô Masahira, and one of the shogun's court physicians, Oka Rekisen'in, were among many others also dismissed from their positions and placed under house arrest.
In a later round of purges in 1859/8, Tokugawa Yoshinobu was forced to retire from his position as head of the Hitotsubashi Tokugawa clan and to enter house confinement; Tokugawa Yoshiatsu and his father Tokugawa Nariaki were also sentenced to house confinement along with their karô Nakayama Nobutomi. A number of former and current bugyô and other figures prominent in foreign affairs in preceding years, including Nagai Naoyuki, Iwase Tadanari, Kawaji Toshiakira, Asano Nagayoshi, and Ôkubo Tadahiro were also stripped of their positions and/or stipends and/or were sentenced to house confinement. A number of high-ranking Mito domain retainers including Ajima Tatewaki, Chinone Iyonosuke, and Ukai Kichizaemon were sentenced to death, while Kichizaemon's son Ukai Kôkichi was imprisoned, and Mito domain retainer Ayuzawa Idayu was banished to an outer island along with Kobayashi Yoshisuke, a shotaifu retainer to the Takatsukasa family. Confucian scholar Ikeuchi Daigaku was also exiled at this time, and Tsuzaki Noriko, a female elder (Rôjo) in service to the Konoe family was imprisoned. Tokugawa Yoshiatsu, Nakayama Nobutomi, and Tsuzaki Noriko were released by the end of the 9th month.
That same month (1859/9), shogunate officials Udono Nagatoshi, Kurokawa Kahei, Hirayama Yoshitada, Hiraoka Enshirô, and Takasu Tetsujirô were also dismissed from their posts and forced into house confinement. The following month (1859/10), Hashimoto Sanai, Rai Mikisaburô, and Iizumi Kinai were sentenced to death, former lord of Tosa han Yamauchi Yôdô to house confinement, and several dozen others to varying degrees of banishment or house confinement as well. Wakadoshiyori Hongô Yasukata and Yoriai Ishikô Masahira were among those forced into retirement and into house confinement; Yoriai Sasaki Akinobu was also reduced in rank at this time.
While the Purge helped Naosuke consolidate power in the hands of his supporters, it also contributed significantly to the anger of his opponents, leading eventually to his assassination in 1860 in the Sakuradamongai Incident.
- Marco Tinello, "The termination of the Ryukyuan embassies to Edo : an investigation of the bakumatsu period through the lens of a tripartite power relationship and its world," PhD thesis, Università Ca' Foscari Venezia (2014), 271n430, 273-274.
- Ishin Shiryô Kôyô 維新史料綱要, vol 2 (1937); vol 3.
- Ishin Shiryô Kôyô 維新史料綱要, vol 2 (1937), 597.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 4, 5, 7.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 6-7, 40.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 7.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 209-210.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 221.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 217.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 224-225.
- Ishin Shiryô Kôyô 維新史料綱要, vol 3 (1937), 230.