In the late Kamakura period, middle and small classes of gokenin who supported the Shogunate not only had to increase their expenditures for military service in the Kyushu area to provide against the invasion of the Yuan Dynasty, but also became gradually insignificant and impoverished due to the penetration of the money economy and divided succession.
鎌倉時代後期には、異国警固などの出費が増大しただけでなく、貨幣経済の浸透や分割相続制によって幕府を支える中小御家人の零細化・疲弊が進んでいた。