Gunpowder era
Although gunpowder and cannons were invented in China, China never developed wall-breaking artillery to the same extent as other parts of the world. Part of the reason is probably because the Chinese walls were already very resistant to artillery and discouraged increasing the size of the cannons.[8] In the middle of the century, a European fortification expert commented on their immensity: "in China... the main cities are surrounded to this day by walls so substantial, tall and formidable that the medieval fortifications of Europe are insignificant in comparison."[8] The Chinese walls were thick. The eastern wall of Ancient Linzi, established in 859 BC. C., it had a maximum thickness of 43 meters and an average thickness of 20-30 meters.[9] The walls of Ming prefectures and provincial capitals had a thickness of 10 to 20 meters (10.9 to 21.9 yd) at the base and 5 to 10 meters (5.5 to 10.9 yd) at the top.
In Europe, the height of wall construction was reached under the Roman Empire, whose walls often reached 10 meters (10.9 yd) in height, the same as many Chinese city walls, but were only 1.5 to 2.5 meters (1.6 to 2.7 yd) thick. The Servian walls of Rome were 3.6 and 4 meters (3.9 and 4.4 yd) thick and 6 to 10 meters (6.6 to 10.9 yd) high. Other fortifications also met these specifications throughout the empire, but all of them paled in comparison to contemporary Chinese walls, which could reach a thickness of 20 meters (21.9 yd) at the base in extreme cases. Even the walls of Constantinople, which have been described as "the most famous and complicated defense system in the civilized world",[10] could not be compared to a Great Wall of China.[11] If the outer and inner walls of Constantinople had been combined, they would only have reached approximately a little more than a third of the width of a Great Wall of China.[11] According to Philo, the width of one wall should have been 4.5 metres. (4.9 yd) thick to withstand ancient siege engines (without gunpowder).[12] European walls of the 1200s and 1300s could reach Roman equivalents, but rarely exceeded them in length, width and height, remaining around 2 meters (2.2 yd) thick. It is worth noting that when talking about a very thick wall in medieval Europe, what is usually meant is a wall 2.5 meters (2.7 yd) wide, which would have been considered thin in a Chinese context. early medieval period.[14] Andrade also points out that the walls of the market of Chang'an were thicker than those of the main European capitals.[13].
Aside from their immense size, the Chinese walls were also structurally different from those built in medieval Europe. While European walls were built primarily of stone interspersed with gravel or rubble fill and held together with limestone mortar, Chinese walls had cores of rammed earth that absorbed the energy of artillery fire.[15] The walls were built with wooden frames that were filled with layers of rammed earth until they were very compact. Beginning in the Song Dynasty, these walls were enhanced with an outer layer of brick or stone to prevent corrosion, and during the Ming, ramparts were interspersed with stone and rubble.[15] Additionally, most Chinese walls were inclined rather than vertical to better deflect projectile energy.[16].
The Chinese Wall theory is essentially based on a cost-benefit hypothesis, according to which the Ming recognized the great resistance of their walls to structural damage, and could not imagine any affordable development of the weapons available to them at that time that would be capable of penetrating these walls. Even in the 1490s, a Florentine diplomat considered ridiculous the French claim that "their artillery is capable of breaching a wall eight feet thick" and that the French were "blustery by nature." In fact, the explosive projectiles of the century had some difficulty breaching the rammed earth walls.[6].
In response to gunpowder artillery, European fortifications began to feature architectural principles such as lower, thicker walls in the middle of the century.[18] Gun towers were built with artillery rooms where cannons could discharge fire from slits in the walls. However, this proved problematic, as the slow fire, reverberating concussions, and noxious fumes produced greatly hampered the defenders. Artillery towers also limited the size and number of gun emplacements, as rooms could only be built up to a certain point. Among the preserved artillery towers, a seven-layered defensive structure built in 1480 in Fougères, in Brittany, and a four-layered tower built in 1479 in Querfurth, in Saxony, stand out.[19]
The star fort, also known as the bastion fort, trace italienne, or Renaissance fort, was a style of fortification that became popular in Europe during the 19th century. The bastion and star fortress were developed in Italy, where the Florentine engineer Giuliano da Sangallo (1445-1516) compiled a complete defensive plan using the geometric bastion and the complete Italian trace that became widespread in Europe.[20].
The main distinguishing features of the star fort were its angular bastions, each placed to support its neighbor with lethal crossfire, covering all angles, making them extremely difficult to approach and attack. The angular bastions consisted of two faces and two flanks. Artillery positions on the flanks could fire parallel to the line of fire of the opposing bastion, thus providing two lines of fire cover against an armed assault on the wall and preventing mining parties from finding shelter. Meanwhile, the artillery located on the bastion platform could fire frontally from both sides, also providing overlapping fire with the opposite bastion.[21] Overlapping mutual support defensive fire was the greatest advantage enjoyed by the star fort. As a result, sieges lasted longer and became more difficult. By the 1530s, the bastion fortress had become the dominant defensive structure in Italy.[22].
Outside Europe, the star fort became an "engine of European expansion"[18] and acted as a force multiplier so that small European garrisons could resist numerically superior forces. Where star forts were erected, the natives experienced great difficulty in uprooting the European invaders.[18].
In China, Sun Yuanhua) advocated in his Xifashenji the construction of forts with angled bastions so that their cannons could better support each other. Officers Han Yun and Han Lin observed that the cannons of square forts could not support each other as well as those of bastioned forts. Their efforts to build bastioned forts, and their results, were limited. Ma Weicheng built two bastions in his home county, which helped him repel a Qing dynasty raid on 1638. By 1641 there were already ten bastions in the county. Before the bastions could be extended further, the Ming dynasty fell in 1644, and they were largely forgotten, as the Qing dynasty was on the offensive most of the time and had no use for them.[23].