As the activity of villains increased and the trend of vassals revolting against their lords became more commonplace during the period of Northern and Southern Courts (Japan), the traditional way in which warfare was conducted began to make the transition from a one-to-one combat to a group battle strategy, and the utilization of ashigaru even spread to the suppression of local and provincial uprisings.
南北朝時代(日本)に悪党の活動が活発化し下克上の風潮が流行すると、伝統的な戦闘形態は個人戦から集団戦へと変化し始め、足軽の活躍の場は土一揆・国一揆にも広まった。