TAIRA no Tadatsune who was a descendant of TAIRA no Masakado raised a revolt and the Imperial Court dispatched a punitive force, but they could not suppress it for over three years.
平将門の子孫に当たる平忠常が乱を起こし、朝廷は討伐軍を派遣するが3年にわたって鎮圧できなかった。