The most familiar characteristics of the traditional Japanese castle are the huge sloping stone walls and the graceful yet militarily sophisticated structures built on top of them. This title covers the entire period of Japanese castle development from the first introduction of stone walls and tower keeps in the mid-16th century, through the period of the great sieges of Japanese history - Nagashino (1575), Kitanosho (1583), Odawara (1590), Fushimi (1600), Osaka (1615) and Hara (1638), the last of the battles that brought an end to a period of intense internal strife known as the Sengoku Jidai (Age of Warring Battles).