After Tokugawa Ieyasu’s victory at Sekigahara, the Tokugawa family built a political system that combined shogunal rule (the bakufu) with semi-autonomous domains (han) ruled by daimyō. This “bakuhan” structure set the problem the shogunate needed to solve: how to prevent powerful regional lords from rebuilding armies and challenging Edo.
The shogunate issued the Buke shohatto (Laws for the Military Houses) to regulate daimyō behavior, including limits on alliances and a strong role for the shogunate in approving sensitive actions. These rules became a foundation for later domain-control tools, including sankin-kōtai, by defining what daimyō could and could not do.
Following the end of major civil wars, the shogunate moved to reduce the military threat from domains by limiting castles and tightening oversight of repairs. By restricting fortifications, domains had fewer strongholds for rebellion and became more dependent on shogunal permission for major defensive construction.
In 1635, Shōgun Tokugawa Iemitsu formalized sankin-kōtai (“alternate attendance”), requiring most daimyō to spend regular periods in Edo while also maintaining authority in their home domains. The system increased surveillance of lords at the shogunate’s center and made coordinated rebellion harder.
A core enforcement mechanism was that a daimyō’s wife and heir typically lived in Edo for long periods, effectively as hostages under shogunal supervision. This raised the personal cost of disloyalty and helped ensure daimyō compliance even when the lord was back in his domain.
Sankin-kōtai required domains to maintain large Edo residences (daimyō yashiki) to house the lord, his retinue, and officials conducting domain business while in the capital. These estates tied domain administration to Edo and reinforced the idea that domains operated under shogunal monitoring.
The mandated trips to and from Edo (often in large, formal processions) and the upkeep of multiple residences imposed major recurring expenses on domains. This financial burden was not an accident: it reduced the ability of daimyō to stockpile resources for war and increased dependence on stable relations with the shogunate.
Regular, large-scale daimyō travel created steady demand for roads, inns, and shipping services along key routes, helping improve communications between Edo and the provinces. Merchants followed the money, expanding trade networks that linked castle towns and the shogunate’s capital.
In 1657, the Great Fire of Meireki devastated Edo, destroying much of the city, including many daimyō mansions and parts of Edo Castle. The disaster forced large-scale rebuilding and provided the shogunate a chance to reorganize urban space, including where elite residences could be located.
After the fire, the shogunate relocated and reassigned many daimyō estates, including moving some major residences outward to create firebreaks and reorganize districts. This rebuilding mattered for governance: the placement of estates influenced surveillance, access to the castle, and how daimyō households interacted with Edo’s administration and economy.
By the mid-1800s, fiscal strain, political conflict, and foreign pressure made it harder for the shogunate to rely on expensive, routine controls like sankin-kōtai. Domains increasingly needed resources for coastal defense and modernization, creating pressure to relax older rules that kept daimyō financially and politically constrained.
In 1862, as part of the Bunkyū-era reforms, the shogunate greatly loosened alternate attendance, reducing required Edo stays and allowing daimyō families to return to their domains. This marked a major shift away from the Tokugawa system of direct social and financial pressure, signaling declining shogunal authority over the domains.
Sankin-kōtai system and domain control under Tokugawa rule (1635–1862)