Second Siege of Gassan-Toda

• Mori Motonari (25,000) vs. Amako Yoshihisa (10,000)
  • Date: September 1565 – January 1566
  • Location: Izumo province
  • KIA: (Amako) Uyama Hisanobu (executed)
  • Castle Siege

Following the death of Amako Haruhisa in 1562 the fortunes of the Amako declined, and in 1564 Mori Motonari began a drive to take all of Izumo. Mori's initial attempts to storm Gassan-Toda failed, so he began capturing the outer Amako forts in an effort to isolate the stronghold. Chief among these outposts was Shiraga, which fell in late 1564 despite Yoshihisa's efforts to provide relief. Motonari then resumed the siege of Gassan-Toda in 1565, and by the end of the year supplies and morale within the castle were flagging. This was exacerbated by Motonari's decision to refuse to accept deserters, a policy aimed at reducing Gassan-Toda's foodstuffs as quickly as possible. Yoshihisa made his situation all the more difficult by executing Uyama Hisanobu on the (incorrect) suspicion of treason. This further damaged morale and when Motonari lifted the ban against accepting deserters, thousands of the starving defenders fled. In January of 1566 Yoshihisa finally surrendered and was allowed to go into exile.