The Murder of Yamana Toyoyuki occurred in the ninth month of Bunmei 3 (1471).  Toyoyuki, while serving as the military governor of Hōki Province, was slayed in Kamo-no-chi in the Yura township of the province.  According to records, he was killed by a traitorous retainer within the Yamana family.

Overview

During this time, military governors in territory controlled by the Yamana clan including Hōki witnessed a weakening of authority as a result of the Ōnin-Bunmei War.  Collateral branches of the Yamana and kokujin, or provincial landowners, took steps to further their autonomy, triggering discord.  In an effort to bring the situation under control, Toyoyuki, as the military governor of Hōki, went from the capital to Hōki around 1469.  He then confronted a rebellion in the family and in the ninth month of 1471, was slayed.  According to one theory, the killing was orchestrated by the Amago clan and powerful kokujin who opposed the Hōki-Yamana at the time.  The incident served as a catalyst to plunge the province and surrounding area into the tumult of the Sengoku period.

Timeline

• Kyōroku 2 (1453) to Ōnin 3 (1469)
  • Yamana Noriyuki transferred the role as the military governor of Hōki Province to his eldest son, Toyoyuki (who acted under the direction of Noriyuki)
• Bunmei 1 (1469)
  • Toyoyuki went from the capital of Kyōto to Hōki
• Ninth month of Bunmei 3 (1471)
  •  Toyoyuki was slayed
• Sixth month of Bunmei 4 (1472)
  • Noriyuki went from the capital of Kyōto to Hōki to end the tumult in the province in the wake of Toyoyuki’s death
• 1/13 of Bunmei 5 (1473)
  • Noriyuki died, followed by further disruption in the Hōki-Yamana family while the province plunged into the chaos of the Sengoku period