Fortress Japanese Castles 250-1540AD Osprey Books

The first primitive fortifications in Japan were built in the Yayoi Period (300 BC-AD 250), when the country was divided into a loose network of clans. However, the first proper fortifications start to be developed with the rise to power of the Yamato Court, the first emperors of Japan in around AD 250. These early Japanese dynasties had close ties to both China and Korea and their defensive architecture betrays these influences closely and, with the threat of a Korean invasion in the 7th century AD a number of these Korean-style castles with long stone walls were constructed on the island of Kyushu. As fears of outside threats diminished more attention was devoted to dealing with internal strife and controlling unruly areas, which led to an increasing number of fortifications being constructed. Due to the nature of the terrain in Japan, these fortifications tend to be characterized by earthworks and wooden palisades, and it is these types of fortification that characterize the Heian Period (AD 794 to 1185) and it numerous internal conflicts, culminating in the Gempei War of 1180-85 between the Taira and Minamoto clans that saw the establishment of the Minamoto shogunate. These early wooden and earth castles began to be sited on the top of mountains for additional defence, and became increasingly elaborate in their structures. It is here that the development of the Yamashiro style of fortification begins. By the end of the 15th century these Yamashiro began to be built using stone and, around 1540 the first stone towers, so characteristic of samurai architecture, start to appear. However, in more remote parts of Japan, particularly Okinawa, the Korean style persisted throughout the whole medieval period, until as late as 1609, and it is here that the first fortifications were adapted to the use of fire arms.