An account of the evolution of Japanese defensive architecture and engineering, from early earthworks through to wooden and earth castles and, finally, the emergence of the stone towers that are so characteristic of the samurai.

He also plots the adaptation of Japanese castles to accommodate the introduction of firearms.

The 47th Samurai - Stephen Hunter - A Bob Lee Swagger Novel.
Book Description
In The 47th Samurai, Bob Lee Swagger, the gritty hero of Stephen Hunter's bestselling novels Point of Impact and Time to Hunt, returns in Hunter's most intense and exotic thriller to date.
Bob Lee Swagger and Philip Yano are bound together by a single moment at Iwo Jima, 1945, when their fathers, two brave fighters on opposite sides, met in the bloody and chaotic battle for the island. Only Earl Swagger survived.