Siege of Iwamura Castle

The siege of Iwamura was a military event which occurred in 1572 in Japan, concurrent with Takeda Shingen's push into Tōtōmi Province and the Battle of Mikatagahara. Akiyama Nobutomo, one of Shingen's "Twenty-Four Generals," set his eye on the great yamashiro (mountain castle) of Iwamura when Tōyama Kagetō, the commander of the castle's garrison, fell ill and died.

Akiyama negotiated the castle's surrender with Tōyama's widow, Lady Otsuya, and took it without any bloodshed. The official keeper of the castle, a seven-year-old lord called Gobōmaru, was taken to the Takeda home province of Kai as a hostage. In accordance with the surrender treaty, Lady Otsuya, who was the aunt of Oda Nobunaga, married Akiyama and she remained the lady of the castle.