TAIRA no Yoritsuna, who was the steward of the Hojo Tokuso family (main branch of the Hojo family), avenged a senior vassal Yasumori ADACHI and other vassals of Yasumori's faction, with whom he had conflicts in political lines, in the Shimotsuki Incident in 1285, which was a year after Tokimune HOJO, who was one of the regents of the Kamakura bakufu (Japanese feudal government headed by a shogun), died and Tokimune's son Sadatoki HOJO became the ninth regent.
北条得宗家執事の平頼綱は、鎌倉幕府鎌倉幕府の執権一覧北条時宗が死去し、その子北条貞時が9代執権となった翌1285年（弘安8年）、政治路線で対立していた有力御家人安達泰盛や泰盛派の御家人を霜月騒動で討伐した。