Ancient mound used for defense hints at walled city in Japan
Ancient hilltop earthworks discovered here could offer the first hard evidence of Japan having had a walled city in the seventh century.
|Researchers study the earthworks in the Maehata ruins at Chikushino, Fukuoka Prefecture |
[Credit: Toshiyuki Tsunenari]
It suggests that large-scale earthworks were constructed, along with castles, on a vast and roughly circular boundary. Dazaifu served as the front line for Japan's diplomatic activities in those days.
The connecting fortifications raise the tantalizing possibility that Japan also built walled cities that were seen in China.
It is the first time that earthworks have been found atop a hill here, officials with the Chikushino city board of education said Nov. 28.
The site is inside the Maehata ruins in Chikushino, Fukuoka Prefecture, which have yielded ancient earthenware, and is located about seven kilometers southeast of where the Dazaifu government had its headquarters.
Earthworks were constructed for defensive purposes by piling up and solidifying layers of earth like a wall. The site in Chikushino is 1.5 meters high and about 13.5 meters wide at the base. The mound consists of two layers of earth, with the eastern side sharply sloped.
Surrounding areas were developed for residential use. It is unknown how far the earthworks stretched.
The Dazaifu government served as a primary stronghold for Japan’s dealings with foreign powers.
In the Battle of Baekgang on the Korean Peninsula in 663, Japan sent troops to help the Baekje forces and to fight against the allied forces of Silla and China’s Tang Dynasty.
In the war known as the “Battle of Hakusukinoe” in Japan, however, Japanese troops were defeated by the allied forces of Silla and Tang. Immediately after that, the Dazaifu government moved swiftly to construct Mizu castle, Ono castle and Kii castle on flatlands or hills in preparation for a possible invasion by the allied forces.
“The construction method of the newly discovered earthworks is the same as that of Mizu castle and Ono castle, as well as other sites. Given the construction method and the estimated production years of the earthenware, there is a high possibility that the mound was part of a structure to defend Dazaifu,” said an official with the Chikushino city board of education.
Researchers have a rough idea of the outline of the Dazaifu area, based on walls constructed around castles in the capital of Baekje on the Korean Peninsula and other areas.
The newly discovered earthworks deviate a little from the outline. But some researchers believe the earthworks formed part of a continuous protective wall, a form of construction seen in China but never before in ancient Japan.
Thus, the latest discovery offers a valuable reference in the history of Japan's ancient cities.
“The discovery means that, in addition to castles, a portion of the defensive line that surrounded a city has been discovered for the first time," said Fujio Oda, professor emeritus of archaeology at Fukuoka University. "This makes the discovery extremely important.”
Authors: Matsuo Watanabe and Shunsuke Nakamura | Source: The Asahi Shimbun [December 01, 2016]