The city wall of Beijing was a fortification built around 1435. It was 23.5 km long. The thickness at ground level was 20m and the top 12m. The wall was 15m high, and it had nine gates. This wall stood for nearly 530 years, but in 1965 it gave way to 2nd Ring Road and the loop line subway of Beijing. Only in the southeast, near Beijing Railway Station, stands one part of the wall. Three gates of the city wall are also intact (Desheng Gate, the Yongding Gate and Zhengyang Gate).
Beijing was the capital city of the last three dynasties (the Yuan, Ming and Qing) in the history of China, it has an extensive fortification system, consisting of the Palace city, the Imperial city, the inner city and the outer city. Specifically including the many gate towers, gates, archways, watchtowers, barbicans, barbican towers, barbican gates, barbican archways, sluice gates, sluice gate towers, enemy sight towers, corner guard towers, and moat, it was the most extensive defense system in dynastical China.
After the collapse of the Qing Dynasty in 1911, Beijing's fortifications were dismantled one by one, the Palace city has remained largely intact; the Imperial city only has Tian'anmen remaining intact; the inner city with Zhengyangmen's gate tower and watchtower, Deshengmen's watchtower, the southeastern corner guard tower, and a section of the inner city wall near Chongwenmen remaining intact; and nothing of the outer city remaining intact, with Yongdingmen completely reconstructed in 2004.
The defence system of Beijing during the Ming and Qing dynasties included city walls, moats, gate towers, barbicans, watchtowers, corner guard towers, enemy sight towers, and military encampments both outside and inside the city. These are also combined with the mountains immediately north of the city and the interior Great Wall sections on those mountain ranges.
Beijing's inner city is also called Jingcheng ("capital city") or Dacheng ("big city"). The eastern and western sections were mostly remnants from Yuan's Khanbaliq, while the northern and southern sections were built during the early Ming dynasty in the Hongwu and Yongle eras. The walls were formed from rammed earth surrounded by rocks and followed by bricks on both the interior and the exterior. It had an average height of 12 to 15 metres. The northern and southern sections that were built in the early Ming were thicker than the eastern and western sections that were built in the Yuan dynasty, averaging 19 to 20 metres in thickness, and 16 metres in thickness at the top, forming a trapezoidal cross-section, with parapets at the top. The inner city had nine gates, and four corner towers at the four vertices. there were 3 sluice gates, 172 enemy sighting towers, 11.038 battlements. Immediately outside the city walls were deep moats 30 to 60 metres in width.
The reconstructed Yongdingmen gate towerIn 1553, the 32nd year of the Jiajing era, the outer city was expanded. It is also called "Guocheng" or "Waiguo". Its walls are 28 kilometres in perimeter, 7,5 to 8 metres high, with 12 metres of width at the bottom and 9 metres at the top. Its southeastern corner was built without a vertex to avoid the low swamps in the area, thus fulfilling the legend of when Nüwa was mending the heavens, heaven's northwest was missing and Earth's southeast was sinking.
In the 28th year of the Jiajing era, when the expansion of the outer city was planned, it was originally conceived that smaller box-shaped "minor cities" would be built around the city gates, forming nine smaller boxed minor cities around the nine inner city gates surrounding the inner city, which would be a formidable defense addition to the city. Instead, it was changed later to a second even larger city south of the inner city. Its southern walls encompasses the southern walls of the Temple of Heaven, its eastern and western walls then extend north until becoming parallel with the inner city's eastern and western walls, about 2 kilometres away from touching the inner city walls, this was where the Yuan Khanbaliq's original rammed earth city's eastern and western walls' southern sections laid before being abandoned in the closing years of the Hongwu era during the early Ming dynasty. Dismantling the rammed earth structure of Yuan and taking some of the raw materials, the expanded outer city's northern wall's northeastern and northwestern sections were built, both ending where the inner city's southern walls began. The outer city walls have a perimeter of approximately 60 kilometres, forming a "凸"-character-shaped relationship with the inner city walls. 11 gates were built, 3 each on the eastern, southern, and western walls, and 2 on the northern walls (1 on the northeastern section and 1 on the northwestern section).
In 1550, the 29th years of the Jiajing era, construction began on 3 outer city box-shaped "minor cities", however because of their proximity to inner city gates, where many commoner's houses and shops have sprung up, many buildings needed to be dismantled, the disgruntled commoners forced the abandonment of the project not long after the construction began. In 1553, the 32nd year of the Jiajing era, it was decided that the rest of Yuan Khanbaliq's rammed earthen walls would be dismantled and its raw materials used to complete the outer city walls, eventually forming a "回"-character-shaped relationship with the inner city walls. The plan was to extend the outer city walls to have a perimeter of 70 kilometres, the east and west 17 kilometres, and the north and south 18 kilometres, adding 11 more gates, 176 more enemy sight towers, 2 additional sluice gates outside of Xizhimen and Tonghui River respectively, and 8 more sluice gates at other low swampy areas. The outer city expansion was a grand project greater than any of the capitals of the previous Chinese dynasties, under Yan Song advice, the project was divided into segments, with the southern walls built first, thus adding extra defense to the bustling commercial district south of inner city's Zhengyangmen. The Emperor approved, construction began on the 32nd year of the Jiajing era's 3rd lunar month (it was a leap lunar month), work was finished in the same year's 10th lunar month. The eastern and western walls were planned in the second segment of the project, however due to successive invasions from the Mongols and Manchus, much of the soldiers were brought to the northern frontiers to defend the Great Wall, and thus few could be used for the construction. Moreover, in 1557, a great section of the Forbidden city caught on fire, much of the workers and funds poured into the reconstruction of the palaces. The expansion of the outer city walls was thus never completed. In 1564, the outer city gate's barbicans were built.
[编辑]Outer City walls
Beijing's outer city has a perimeter of 28 li's or 14,409kilometres, it is wide on the east-west horizontal axis, and narrow on the north-south vertical axis. 4 corner guard towers are built on the four corner vertices, along with 7 gate towers. The wall's exterior have bricks averaging 1 metre in width, mostly large bricks from the Ming dynasty, the interior averages 0,7 metres, mostly small bricks from the Qing dynasty. The outer city walls have an average height of 6 to 7 metres, its top has an average thickness of 10 to 11 metres, its base has an average thickness of 11 to 15 metres. The western sections of the outer city walls are the most narrow, averaging only 4,5 metres at the top and 7,8 metres at the base.
The outer city walls, gate towers and corner guard towers were dismantled between 1951 and 1958.
[编辑]Outer City gates
Beijing's outer city has 7 gates, 3 on the southern walls, 1 each on the eastern and western walls, lastly there are also two side gates on the northern walls (on the northeastern and northwestern sections respectively). The outer city gate towers are all smaller in scale than the inner city's gate towers. The grandest in scale is the one laying on the north-south axis of the city, directly south of Forbidden city's Wumen, Imperial city's Tian'anmen and Inner city's Zhengyangmen --- outer city's central southern gate Yongdingmen. Yongdingmen has a gate tower of approximately 20 metres in height, multi-eaved Xieshanding style, 7 rooms by 3 rooms. Just below Yongdingmen's scale is Guangningmen (present-day Guang'anmen), it is only slightly lower in height than Yongdingmen. Guangqumen's, Zuo'anmen's, You'anmen's gate towers are all single-eaved Xieshanding style with only one floor, their heights only a mere 15 metres. The two side gates, Dongbianmen and Xibianmen are even smaller in scale.
The outer city gate had only their barbicans outside of the gate towers during the Ming dynasty. The watchtowers were only built during Qing dynasty's Qianlong era. The watch towers of the outer city are also smaller in scale when compared with the inner city equivalents. Yongdingmen's watchtower is the grandest in scale among the outer city gates' watchtowers, it has two rows of arrow windows with 7 windows in each row. The left and right sides have 2 rows of 3 windows each respectively, amounting to 26 windows in total. There isn't a side tower hugging the interior of the watchtower as with the inner city gates' watchtowers, there is only an archway. Guang'anmen's, Guangqumen's, Zuo'anmen's, and You'anmen's four watchtowers are even smaller in scale, having only 22 windows in each. Dongbianmen's and Xibianmen's watchtowers are the smallest in scale, having only 8 windows. Different from the inner city's barbicans, the outer city's barbicans are all built around the base of the watchtower instead of the base of the gate tower, thus forming a straight line with the gate's archway. There aren't any Guandi Temples built in the barbicans of the outer city gates.