how did the tokugawa shoguns kept control of daimyo during the period of their rule
Tokugawa shogunate The emperor, nominally a religious leader, held no real power; this was invested in the shōgun. The shogunate had the power to discard, annex, and transform domains. The sankin-kōtai system of alternative residence required each daimyō to reside in alternate years between the han and the court in Edo. During their absences from Edo, it was also required that they leave family as hostages until their return. The huge expenditure sankin-kōtai imposed on each han helped centralize aristocratic alliances and ensured loyalty to the shōgun as each representative doubled as a potential hostage.