However, Yoshihiro was provoked by the third shogun, Yoshimitsu ASHIKAGA, who regarded Yoshihiro's power as dangerous, to raise an army in conspiracy with the Kamakura Kubo, Mitsukane ASHIKAGA in Sakai in 1399, but he died in the action (the Oei War).
しかし義弘の勢力を危険視した第3代将軍・足利義満の挑発に乗った義弘は、鎌倉公方の足利満兼と共謀して、応永6年（1399年）に堺で挙兵するも敗死した（応永の乱）。