The siege of Iwamura was a military event which occurred in 1572 in Japan, concurrent with

Takeda Shingen was daimyō, daimyo of Kai Province during the Sengoku period of Japan. Known as "the Tiger of Kai", he was one of the most powerful daimyo of the late Sengoku period, and credited with exceptional military prestige. Shingen was based in a p ...

's push into

Tōtōmi Province was a Provinces of Japan, province of Japan in the area of Japan that is today western Shizuoka Prefecture.Louis-Frédéric, Nussbaum, Louis-Frédéric. (2005). "''Tōtōmi''" in . Tōtōmi bordered on Mikawa Province, Mikawa, Suruga Province, S ...

and the

Battle of Mikatagahara The took place during the Sengoku period of Japan between Takeda Shingen and Tokugawa Ieyasu in Hamamatsu, Mikatagahara, Tōtōmi Province on 25 January 1573. Shingen attacked Ieyasu at the plain of Mikatagahara north of Hamamatsu during hi ...

Akiyama Nobutomo was a samurai during the Sengoku period in Japan. He is known as one of the "Twenty-Four Generals of Takeda Shingen". Nobutomo also served under Shingen's son, Takeda Katsuyori. Biography In 1527, Akiyama Nobutomo was born at in Kai provi ...

, 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 Lady Otsuya, who was not only Tōyama's widow but the aunt of

Oda Nobunaga was a Japanese ''daimyō'' and one of the leading figures of the Sengoku period, Sengoku and Azuchi-Momoyama periods. He was the and regarded as the first "Great Unifier" of Japan. He is sometimes referred as the "Demon Daimyō" and "Demo ...

. The heir to the castle was a four-year-old boy called Gobōmaru, the fifth son of Oda Nobunaga, who had been given to Tōyama to adopt and raise as his own. Gobomaru was taken to the Takeda home in Kai province as a hostage. In accordance with the surrender treaty, Lady Otsuya married Akiyama. This caused the Takeda-Oda relationship to decline and Nobunaga started a campaign against the Takeda clan.

References

*Turnbull, Stephen (1998). ''The Samurai Sourcebook''. London: Cassell & Co. Sieges of the Sengoku period 1572 in Japan Conflicts in 1572 Military history of Gifu Prefecture Mino Province Attacks on castles in Japan Ena, Gifu 16th-century military history of Japan {{Japan-battle-stub