Karō (家老, house elder) were top-ranking samurai officials and advisors in service to the daimyo of feudal Japan.In the Edo period, the policy of sankin kōtai (alternate attendance) required each daimyo to place a karō in Edo and another in the home han (feudal domain). A karō who was in charge of a castle was called the jōdai karō (城代家老), while the one in Edo was called the Edo karō (江戸家老).