The kuni no miyatsuko served as important government officials at the Yamato Court, with the position most likely being created during the reign of Emperor Seimu. Many were in charge of various provinces and had much power. The kuni no miyatsuko replaced the agatanushi, or provincial chiefs, in many areas. This network of kuni no miyatsuko created an administrative web across the country that allowed the Yamato court unprecedented power.

The position was appointed by the court, and many kuni no miyatsuko were members of the Yamato family or its allies. At several points during the period, there were over 100 kuni no miyatsuko on record. In addition to their government duties, kuni no miyatsuko could be called upon to lead military forces, oversee religious rituals, present gifts and duty to the court, and entertain court representatives when they were in the area.

The Taiku reforms reduced the power of the kuni no miyatsuko and revoked their power to rule provinces. While the post remained long after the reforms, the kuni no miyatsuko eventually shifted from a political post to a religious and spiritual one. By the ninth century, the position had declined to more or less simply the title, and even that soon vanished.