Sankin-kōtai
Sankin-kōtai (Japanese: 参覲交代/参覲交替, now commonly written as 参勤交代/参勤交替, 'alternate attendance') was a policy of the Tokugawa shogunate during most of the Edo period, created to control the daimyo, the feudal lords of Japan, politically, and to keep them from attempting to overthrow the regime. It required most daimyo to alternate between living in their domain and in the shogunate's capital, Edo, every year.