In the Muromachi period, shugo (provincial constables) became powerful and lowered official positions of jito and kokujin (local samurai) from the Kamakura period including zaichokanjin (local officials in the Heian and Kamakura periods) and started to control the lands owned by kokuga, jito, or kokujin with the goal to establish the shugo-ryogoku system (the system where a shugo dominates a manor).
室町時代になると、守護の権力が強大化し、守護領国制の成立を目指して、在庁官人を含む鎌倉期の地頭、国人を被官化し、国衙や彼らの所持していた領地を掌握し始めた。