After Yoshimune, the eighth shogun, established the Gosankyo (Three Lords: three junior collateral houses of the Tokugawa family), the position of karo (chief retainers) at these families were considered to be equivalent in the status to the keepers of Edo-jo Castle.
8代将軍吉宗が御三卿を創設してからは、その家老職も江戸城留守居に準ずる地位とされた。