Military Defense in Ancient Cities: Walls and Gates

With wars commonly waged in ancient China, the mechanism for defense and protection such as city walls, trenches and moats were created out of sheer necessity, but inadvertently led to the development and building of cities. The creation of enclosed cities meant that the most important form of protection were city walls.

The earliest types of city walls which were used were simply wooden fences, piled rocks or tamped earth. Before the Song Dynasty, city walls were rarely layered with bricks. However, the invention of gunpowder and its subsequent use in the attacks of cities brought about unprecedented destruction. As a result, some important cities began to fortify the critical defense points of their cities with brick walls.

After the Ming Dynasty, brick-fortified city walls became even more widespread. The height and thickness of the walls depended on the defend strategies of the cities. Battlements and watch towers also differed in size and numbers, depending on how the cities were ranked, in terms of importance.

The city wall of the ancient Pingyao city
The ancient Pingyao city of Shanxi Province has one of the most well-preserved city wall in China, which were built between 872BC-782BC. In the beginning, the city walls were made of tamped earth. The city walls then underwent several times of rebuilding and repair during the Ming and Qing dynasties. Today, the city wall spans 6,163 meters in length, with a core wall of tamped earth that was fortified with an outer layer of bricks. It has a thickness of 10 meters at the bottom and 3-5 meters on top, as well as a height ranging from 6-10 meters. The city also has 6 enclosures for defense outside the city wall, a total of 3,000 battlements and 72 watch towers. This well-fortified city of bricks, granite and moats has weathered attacks and natural disasters well throughout the course of the centuries.

The city wall of ancient Nanjing city
The ancient city of Nanjing, which was built during the Ming Dynasty, has been recognized by all as the first bridck-walled city of China. The building of the city commenced in 1366 and was a consolidation of the capital cities built by previous dynasties at the same location. The height of the city wall ranged between 14 and 21 meters, while the width of the bottom of the wall was about 14 meters. The width of the top of the wall was between 4 and 9 meters. Altogether, Nanjing city had a total of 13 gate entrances along its wall and every single entrance was double-gated, with a floodgate in front and a twin set of timber doors encased in metal behind.

Nanjing city was the product of the labor and intelligence of civilians from the provinces located in the mid-lower half of the Yangtze River. The manufacture of the bricks for the city wall was of the strictest quality control, with the origins of manufacture and the names of manufacturer as well as the quality controller stamped onto each brick.

To further fortify the wall, granite rocks were used to build the foundation and a binding paste of lime, tung oil and glutinous rice mixture were used for sealing and binding the bricks together. This accounts for the sturdiness of the wall even after 600 years.

source: Chinese Architecture, published by China International Press