In the Ritsuryo system (a system of centralized government based on the ritsuryo code), the term kaieki referred to removing someone from their current post and appointing someone new to that position. In the Kamakura and Muromachi periods, the term kaieki referred to making changes to the duties of Shugo and Jito (military governors and estate stewards).
In the Edo period, the term kaieki referred to a punishment to samurai, including territorial lords (called "daimyo") and direct vassals of the shogun (called "hatamoto"), by which they were deprived of their status as samurai, along with their territories, castles and residences. Kaieki can also be expressed as the Japanese word jofu. Also, having the size of lands in possession reduced is called genpo in Japanese. Kaieki in the Edo period is described below.
Kaieki applied to Daimyo families in the Edo period
In the Edo period, when a Daimyo family became subject to kaieki, they were beheaded (Katsuike MATSUKURA in the Shimabara War, for example) or were forced to carry out Seppuku (suicide by disembowelment) (Naganori ASANO in the Genroku Ako Incident, for example) if they committed a serious crime. Or, they may have been forced to stay with a different Daimyo family to live under strict surveillance (Tadanao MATSUDAIRA and Tadateru MATSUDAIRA, for example).
Castles and lands were confiscated, and so many vassals could no longer receive a stipend and became ronin (masterless samurai). Note, however, many Daimyo were forgiven after receiving the kaieki decision and continued their family line as they or some of their descendents were appointed as feudal lords or direct vassals of the shogun. Also, there were some cases where Fudai and Shinpan (hereditary daimyo and relatives of the Tokugawa family) were forgiven after receiving the kaieki decision, and their descendents returned to the original positions to receive almost the same stipend.
After the Battle of Sekigahara, 88 Daimyo families that joined the West army, such as Mitsunari ISHIDA (Omi), Yukinaga KONISHI (Higo), Hideie UKITA (Bizen Okayama), and Morichika CHOSOKABE (Tosa), were subjected to kaieki, and also, 5 Daimyo families such as the Mori clan (Terumoto MORI) and Uesugi clan (Kagekatsu UESUGI) were subjected to a severe genpo.
During the war-free period after the Siege of Osaka, kaieki was mainly applied as punishments for the extinction of a family line or breach of the Shogunate law. Since it was prohibited for a Daimyo to apply for an adoption of a son after becoming seriously ill, many Daimyo families suffered kaieki as a result of the extinction of lineages. Also, Masanori FUKUSHIMA was subjected to kaieki for violation of the Shogunate law when he tried to repair Hiroshima-jo Castle without permission. Furthermore, there were Daimyo such as Tadachika OKUBO and Masazumi HONDA who were subject to kaieki because they lost the power struggle inside the bakufu (Japanese feudal government headed by a shogun).
In the early Edo period, the Daimyo system abolishment measure was implemented mainly targeting Daimyo of the former Toyotomi family. As a result, during the three Tokugawa generations of Ieyasu, Hidetada, and Iemitsu, 82 Tozama Daimyo (nonhereditary feudal lord) families and 49 Fudai and Shinpan (hereditary daimyo and relatives of the Tokugawa family) families were subject to kaieki.
The Edo shogunate gradually established its domination by turning territories that were left unoccupied as a result of kaieki or genpo into shogunate territories and by allocating these territories to the relatives and hereditary vassals of the Tokugawa family and transferring feudal lords unrelated to the family to remote territories.
Meanwhile, however, there were many ronin because of kaieki, and this caused social unrest to grow and finally resulted in a rebellion (Keian Incident). For this reason, the bakufu reviewed its policy and the Matsugo yoshi no kin (ban on adoption of a son on one's deathbed) was loosened during the time of the fourth shogun Ietsuna TOKUGAWA.
During the time of the fifth shogun, Tsunayoshi TOKUGAWA, the target of the Daimyo abolishment measure shifted to Fudai Daimyo (a daimyo of a hereditary vassal to the Tokugawa family), and as a result, 27 families were subjected to kaieki. The shogunate system was established afterwards and accordingly, the application of kaieki and transfers decreased, and the allocation of Daimyo was fixed until the end of the bakufu.
After the Battle of Sekigahara through the Edo period, a total of 248 families consisting of 127 Tozama Daimyo families and 121 Shinpan and Fudai Daimyo families were subject to kaieki. After the Toyotomi clan was destroyed in the Siege of Osaka, no more Daimyo attempted armed resistance and all handed over their castles and lands to the bakufu without resistance.
At the end of the Edo period, the Choshu clan defeated the bakufu army through armed resistance (the Choshu Conquest), the bakufu dramatically lost its power and absolute control over the Daimyo, and the shogunate system was destroyed as a result of the Boshin War that occurred after the Battle of Toba-Fushimi.
After the Boshin War, the new Meiji government subjected one family (Jozai clan) to kaieki and 22 families, such as the Aizu and Sendai clans, to genpo. Note that, immediately before Haihan-chiken (abolition of feudal domains and establishment of prefectures) occurred, Nagatomo KURODA of the Fukuoka Domain was forced to resign as the governor of the domain due to the fake bill incident and Imperial Prince Arisugawanomiya Taruhito was appointed to take over the position. This was generally considered to be kaieki because the governor position could be hereditary like the lord position even after lands and people were returned to the Emperor.
Major reasons for applying kaieki
Military reasons (the Battle of Sekigahara and the Siege of Osaka)
Extinction of a family line
Breach (illegal extension or reconstruction of castles or illegal marriage) of the Shogunate law (Buke Shohatto [code for the warrior households])
Failure to properly control territories (family troubles or peasant revolts)
Misconduct or outrageous behavior due to mental instability
Kaieki or genpo applied to Daimyo families that lost in the Battle of Sekigahara
Loss in the Battle of Sekigahara
Being in the West army in the Battle of Sekigahara
Escaped from the Battle of Sekigahara
Remained neutral in the Battle of Sekigahara
Daimyo that were subjected to kaieki during the Edo era
Although we have no examples of Daimyo being subjected to kaieki, one of the most common reasons for the kaieki of ordinary samurai was the running away (flight or escape from one's domain) of the current or former heads of households.
When this occurred, kaieki was applied even though there was a successor, and when those who had run away were captured, they were sometimes executed because they were 'not loyal.'
There were some cases where those who were once subject to kaieki received amnesty, but it would only allow them to serve the lord that they had served before kaieki, and there were only a few cases in which they returned to their services and received the same amount of stipend as they had received before kaieki.