Yoshitsune's remarkable military contributions in defeating the Taira clan were mainly achieved with the participation of the Saigoku (western Japan) warriors, and this lead to a deprivation of Togoku (eastern Japan) warriors' opportunities to render distinguished services, and consequently, provoked the discontent of the lower-ranking vassals (gokenin) of eastern Japan.
主に西国武士を率いて平氏を滅亡させた義経の多大な戦功は、恩賞を求めて頼朝に従っている東国武士達の戦功の機会を奪う結果になり、鎌倉政権の基盤となる東国御家人達の不満を噴出させた。