Sankin-kotai (daimyos alternate-year residence in Edo) (参勤交代)
Sankin-kotai is one of the Edo bakufu (Japanese feudal government headed by a shogun)'s system that obligated daimyo (Japanese feudal lords) to reside in Edo periodically. Sankin means that daimyo served for the lord (Seii-Taishogun [literally, "great general who subdues the barbarians] in this case) for a certain period, while kotai means that they returned to their domains on leave to attend to government affairs there.
As the provision mentioning Sankin-kotai in the 1635 edition of Buke Shohatto (code for the warrior households) said, "大名小名在江戸交替所相定也毎歳夏四月中可致参勤従者之員数…"(we announce the establishment of daimyo's sankin-kotai. Daimyo are required to arrive at Edo in every April. Too many retainers are employed recently...), "参勤" and "交替"were used.
During the Sengoku Period, some Sengoku daimyo (Japanese territorial lord in the Sengoku period) allowed their subjects to reside in their castle towns and Hideyoshi TOYOTOMI set up the residences near Osaka Castle, Jurakudai, Fushimi Castle for his subjects and their families. This system became the prototype of the nationwide sankin-kotai. Daimyo lived in their lord's place and their own feudal domains each for one year.
Establishment of the system
After Ieyasu TOKUGAWA won the Battle of Sekigahara in 1600 and attained supremacy, various daimyo started to make their pilgrimage to Edo to gain the Tokugawa clan's favor. Following Hideyoshi's footstep, Ieyasu prepared the samurai residences near Edo-jo Castle so that daimyo's families would live in Edo. In the beginning, daimyo's sankin-kotai was voluntary, but it gradually became established as a system, and the 1635 edition of Buke Shohatto, issued in the era of Iemitsu TOKUGAWA, the third Shogun, made it obligatory.
In 1642, fudai daimyo (hereditary vassals to the Tokugawa family) were required to live in Edo and their own feudal domains each for one year, which meant that all daimyo excluding the cabinet officials of the Shogunate were subject to sankin-kotai, in principle.
The sankin-kotai system was firmly maintained throughout the Edo period except during the era of Yoshimune TOKUGAWA, the eighth Shogun, when the regulations were partially relaxed because of financial difficulty.
In leap August 1862, daimyo were permitted to serve in Edo for one hundred days once every three years as part of the Bunkyu Reform. In September 1864, the Edo bakufu, misinterpreting the post Kinmon Incident situations, brought the system back to the original form, but many domains did not follow the bakufu's policy.
Under the sankin-kotai system established in 1635, daimyo, in addition to residing in Edo and their own feudal domains each for one year, leaving their own families in Edo permanently as hostages, had to pay their own travel costs and living costs in Edo. But some Shinpan (Tokugawa's relatives) and fudai daimyo like the Mito Tokugawa family, exempted from sankin-kotai, resided in Edo permanently because their demesnes were located near Edo or small. They were called "jofu." Edo hatamoto (direct retainers of the Edo bakufu) of high social status called kotaiyoriai were subject to sankin-kotai like daimyo.
The sankin-kotai system reportedly aimed to curb daimyo's power for uprisings or rebellious acts by putting financial burdens on them. But because the bakufu introduced the system for military service, clans' failure to do military service owing to their financial difficulty was detrimental to the foundation of the system, which led the bakufu to take measures such as restricting daimyo-gyoretsu (daimyo's procession).
Because sankin-kotai was a military service, daimyo had to move with a great number of their subordinate warriors, which traveling took the form of a large-scale march called daimyo-gyoretsu. Sankin-kotai was so costly that it placed an enormous financial burden on daimyo accordingly.
On the other hand, because of sankin-kotai, roads and shukuba (post stations) were maintained. In addition, a party of daimyo gyoretsu spent so much that they enjoyed economic prosperity. At the same time, because a great number of daimyo's attendants traveled back and forth between Edo and the provinces, Edo culture spread nationwide via them. For example, the sankin-kotai carried out by Nariyuki TOKUGAWA, the eleventh lord of the Kishu Tokugawa Family in 1841 consisted of 1639 warriors, 2337 laborers, 103 horses. Shichiri-bikyaku (express messengers) and feudal retainers of the Kishu clan reportedly arrived at Hirakata-juku Station, one station along the trip, for preparation several months earlier than the lord would do. The procession consisting of several thousand people indicates that a large amount of expenses were consumed for the trip including the prior arrangements. The daimyo gyoretsu carried out by the Kishu Tokugawa family, one of three privileged branches of the Tokugawa family, were so gorgeous and prestigious that many peasants spared the time to see the scene. The Kishu Tokugawa family's daimyo gyoretsu were exceptional, but other daimyo gyoretsu also had huge economic (money expended and so on) and cultural effects (social status and so on) on the areas along which the procession occurred.
The clans that were not so rich, while cutting costs, reportedly employed 'additional' retainers on a temporary basis to maintain the dignity of the procession only when it passed by major shukuba-machi (post stations).
When a clan was exempted from sankin-kotai for certain reasons, this was called "yosha"(literary means forgiveness). Yosha applied when the castle of a daimyo was destroyed by fire, famine occurred, the lord of domain was sick, or a new lord took over the domain and so on.
Because a large number of vassals of each clan went to Edo leaving their families in their domains owing to sankin-kotai, warriors accounted for about half the population in Edo.