Japanese Castle - History

History

Originally conceived of purely as fortresses, their primary purpose being military defence, Japanese castles were originally placed in strategic locations, along trade routes, roads and rivers. Though castles continued to be built with these considerations in mind, for centuries fortresses were also built to serve as centres of governance. By the Sengoku period, they had come to serve as the homes of daimyo (feudal lords), and served to impress and intimidate rivals not only with their defences, but with their size and elegant interiors, architecture and decorations. Oda Nobunaga was one of the first to build one of these palace-like castles, at Azuchi Castle in 1576; this was Japan's first castle to have a tower keep (天守閣, tenshukaku), and it inspired both Toyotomi Hideyoshi's Osaka Castle and Tokugawa Ieyasu's Edo Castle. Azuchi served as the governing center of Oda's territories, and as his lavish home, but it was also very keenly and strategically placed. A short distance away from the capital of Kyoto, which had long been a target of violence, Azuchi's carefully chosen location allowed it a great degree of control over the transportation and communication routes of Oda's enemies.

Prior to the Sengoku period (roughly, the 16th century), most castles were called yamajiro (山城), or 'mountain castles'. Though most later castles were built atop mountains or hills, these were built from the mountains. Trees and other foliage were cleared, and the stone and dirt of the mountain itself was carved into rough fortifications. Ditches were dug, to present obstacles to attackers, as well as to allow boulders to be rolled down at attackers. Moats were created by diverting mountain streams. Buildings were made primarily of wattle and daub, using thatched roofs, or, occasionally, wooden shingles. Small ports in the walls or planks could be used to deploy bows or fire guns from. The main weakness of this style was its general instability. Thatch caught fire even more easily than wood, and weather and soil erosion prevented structures from being particularly large or heavy. Eventually, stone bases began to be used, encasing the hilltop in a layer of fine pebbles, and then a layer of larger rocks over that, with no mortar. This support allowed larger, heavier, and more permanent buildings.