The Soryo system (the eldest son system as the succession of the head of the family) was made as a base to rule over gokenin (immediate vassal of the shogunate during the Kamakura and Muromachi through Edo periods) by bakufu during the Kamakura period.
鎌倉時代において、幕府は惣領制を御家人支配の基盤とした。