The years between the battle of Sekigahara and the siege of Osaka witnessed the most furious spate of castle-building and redevelopment in Japanese history. This was the beginning of what would become two and a half centuries of peace under the iron rule of the Tokugawa. One major element in their polity was the baku-han system, whereby national government was provided by the bakufu or Shogunate, and local government by the daimyô’s fiefs or han. Like everything else in Tokugawa Japan, there were regulations governing the daimyô’s castles, which became the focal point for local administration. Yet along with the rebuilding and redevelopment of provincial castles, many were destroyed under the policy of ‘one province – one castle’. The result was that the mighty fortresses we see today became the centre of a daimyô’s territory in a more decisive and defined way than ever before.
When wars ceased the castles also became the focus of the castle towns that had grown up beside them, and these in turn were to become the Japanese cities of today. Commerce flourished, particularly in Edo and Osaka, but tragedy struck many old castles in the mid-19th century. The influence of the shogun had long been declining in the face of western incursions, and there were moves afoot for the abolition of the Shogunate and the restoration of imperial power. Several rebellions broke out, consuming certain famous Japanese castles in their flames, and when the emperor was restored Japan looked to the future, not to the past. The castles became the symbols of an old-fashioned and discredited system that modern Japan had left behind. They also provided possible bases for rebellion, a fact brought home by the Satsuma Rebellion of 1870, which included a siege of Kumamoto castle. So in the desire to be modern and progressive many castles were demolished, and others were allowed to retain only their keeps.
The final phase of destruction happened during the bombing raids of the final year of World War II, when many castles along the Pacific Coastal area were lost forever. Castles in more remote areas such as Matsue and Matsumoto were untouched, but the overall destruction was considerable. Since then many keeps have been rebuilt, some in reinforced concrete with varying results, others more authentically using the correct materials. The economic success of Japan during the latter half of the 20th century meant that funding was seldom a problem, and with the superb restoration work that has been done on such wonderful original specimens as Himeji and Hikone, the graceful Japanese castle may be enjoyed today as never before.