Although the shogunate set the eldest son system (for the succession of the head of the family) as a foundation for the ruling vassals, in fact, the minor vassals were declining because of the divided succession of bushi class and the eldest son system, and much of the vassal system began to collapse, being buffeted by the progress of a monetary economy.
幕府は惣領制を御家人支配の基盤としたが、実はこの時期、武士団分割相続と惣領制により中小御家人は零細化し、そして貨幣経済の進展に翻弄されて多くは崩壊を初めていた。