n attack on a walled town ,
Yuan dynasty , Poland, made of field stone and bog iron
Mesopotamia From very early history to modern times, walls have been a near necessity for every city.
Uruk in ancient
Sumer (
Mesopotamia) is one of the world's oldest known walled cities. Before that, the
proto-city of
Jericho in the
West Bank had
a wall surrounding it as early as the 8th millenniumBC. The earliest known town wall in Europe is of
Solnitsata, built in the 6th or 5th millennium BC. The
Assyrians deployed large labour forces to build new palaces, temples and defensive walls.
Babylon was one of the most famous cities of the ancient world, especially as a result of the building program of
Nebuchadnezzar, who expanded the walls and built the
Ishtar Gate. The Persians built
defensive walls to protect their territories, notably the
Derbent Wall and the
Great Wall of Gorgan built on the either sides of the
Caspian Sea against nomadic nations.
South Asia Some settlements in the
Indus Valley civilization were also fortified. By about 3500BC, hundreds of small farming villages dotted the
Indus floodplain. Many of these settlements had fortifications and planned streets. The stone and mud brick houses of
Kot Diji were clustered behind massive stone flood dykes and defensive walls, for neighboring communities quarreled constantly about the control of prime agricultural land.
Mundigak () in present-day south-east
Afghanistan has defensive walls and square bastions of sun dried bricks.
Southeast Asia The concept of a city fully enclosed by walls was not fully developed in Southeast Asia until the arrival of Europeans. However, Burma serves an exception, as they had a longer tradition of fortified walled towns; towns in Burma had city walls by 1566. Besides that, Rangoon in 1755 had
stockades made of teak logs on a ground
rampart. The city was fortified with six city gates with each gate flanked by massive brick towers. In other areas of Southeast Asia, city walls spread in the 16th and 17th century along with the rapid growth of cities in this period as a need to defend against European naval attack.
Ayutthaya built its walls in 1550 and
Banten,
Jepara,
Tuban and
Surabaya all had theirs by 1600; while
Makassar had theirs by 1634. A sea wall was the main defense for
Gelgel. For cities that did not have city walls, the least it would have had was a stockaded
citadel. This wooden walled area housed the royal citadel or aristocratic compounds such as in
Surakarta and
Aceh. Studies of the ruins and reconstructions of the ancient city walls are currently being undertaken at some sites.
Europe In
ancient Greece, large
stone walls had been built in
Mycenaean Greece, such as the ancient site of
Mycenae (famous for the huge stone blocks of its '
cyclopean' walls). In classical era Greece, the city of
Athens built a long set of parallel stone walls called the
Long Walls that reached their guarded seaport at
Piraeus. Exceptions were few, but neither ancient
Sparta nor ancient
Rome had walls for a long time, choosing to rely on their militaries for defense instead. Initially, these fortifications were simple constructions of wood and earth, which were later replaced by mixed constructions of stones piled on top of each other without
mortar. The
Romans later fortified their cities with massive, mortar-bound stone walls. Among these are the largely extant
Aurelian Walls of
Rome and the
Theodosian Walls of
Constantinople, together with partial remains elsewhere. These are mostly city gates, like the
Porta Nigra in
Trier or
Newport Arch in
Lincoln. In Central Europe, the
Celts built large fortified settlements which the Romans called
oppida, whose walls seem partially influenced by those built in the Mediterranean. The
fortifications were continuously expanded and improved. (
Spain) are one of Europe's best preserved walls.Apart from these, the early
Middle Ages also saw the creation of some towns built around castles. These cities were only rarely protected by simple stone walls and more usually by a combination of both walls and
ditches. From the 12th century AD hundreds of settlements of all sizes were founded all across Europe, which very often obtained the right of fortification soon afterwards. Several medieval town walls have survived into the modern age, such as the
walled towns of Austria,
walls of Tallinn, or the town walls of
York and
Canterbury in England, as well as
Nordlingen,
Dinkelsbühl,
Berching and
Rothenburg ob der Tauber in Germany. In Spain,
Ávila and
Tossa del Mar hosts surviving medieval walls while
Lugo has an intact Roman wall. In medieval warfare, town walls were often targeted for destruction, partly for their role in defence but also because of their role in shaping a settlement's identity, and archaeologist Giulia Bellato, notes "walls were the visible marker that defined a city as such and helped define its inhabitants as citizens". The founding of urban centers was an important means of territorial expansion and many cities, especially in central and eastern Europe, were founded for this purpose during the period of
Eastern settlement. These cities are easy to recognise due to their regular layout and large market spaces. The fortifications of these settlements were continuously improved to reflect the current level of military development.
Gunpowder era Chinese city walls dated to the
Six Dynasties (220～589). Almost all of the original city is gone, but portions of the city wall remain. Not to be confused with the
City Wall of Nanjing. While 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 Chinese walls were already highly resistant to artillery and discouraged increasing the size of cannons. In the mid-twentieth century a European expert in fortification commented on their immensity: "in China ... the principal towns are surrounded to the present day by walls so substantial, lofty, and formidable that the medieval fortifications of Europe are puny in comparison." Chinese walls were thick. The eastern wall of
Ancient Linzi, established in 859 BC, had a maximum thickness of 43 metres and an average thickness of 20–30 metres. Ming prefectural and provincial capital walls were thick at the base and at the top. In Europe the height of wall construction was reached under the
Roman Empire, whose walls often reached in height, the same as many Chinese city walls, but were only thick. Rome's Servian Walls reached in thickness and in height. Other fortifications also reached these specifications across the empire, but all these paled in comparison to contemporary Chinese walls, which could reach a thickness of at the base in extreme cases. Even the walls of Constantinople which have been described as "the most famous and complicated system of defence in the civilized world," could not match up to a major Chinese city wall. Had both the outer and inner walls of Constantinople been combined they would have only reached roughly a bit more than a third the width of a major wall in China. According to
Philo the width of a wall had to be thick to be able to withstand ancient (non-gunpowder) siege engines. European walls of the 1200s and 1300s could reach the Roman equivalents but rarely exceeded them in length, width, and height, remaining around thick. When referring to a very thick wall in medieval Europe, what is usually meant is a wall of in width, which would have been considered thin in a Chinese context. There are some exceptions such as the
Hillfort of Otzenhausen, a Celtic ringfort with a thickness of in some parts, but Celtic fort-building practices died out in the early medieval period. Andrade goes on to note that the walls of the
marketplace of Chang'an were thicker than the walls of major European capitals. Aside from their immense size, Chinese walls were also structurally different from the ones built in medieval Europe. Whereas European walls were mostly constructed of stone interspersed with gravel or rubble filling and bonded by limestone mortar, Chinese walls had tamped earthen cores which absorbed the energy of artillery shots. Walls were constructed using wooden frameworks which were filled with layers of earth tamped down to a highly compact state, and once that was completed the frameworks were removed for use in the next wall section. Starting from the Song dynasty these walls were improved with an outer layer of bricks or stone to prevent erosion, and during the Ming, earthworks were interspersed with stone and rubble. Most Chinese walls were also sloped rather than vertical to better deflect projectile energy. The Chinese Wall Theory essentially rests on a cost benefit hypothesis, where the Ming recognized the highly resistant nature of their walls to structural damage, and could not imagine any affordable development of the guns available to them at the time to be capable of breaching said walls. Even as late as the 1490s a Florentine diplomat considered the French claim that "their artillery is capable of creating a breach in a wall of eight feet in thickness" to be ridiculous and the French "braggarts by nature". Very rarely did cannons blast breaches in city walls in Chinese warfare. This may have been partly due to cultural tradition. Famous military commanders such as
Sun Tzu and
Zheng Zhilong recommended not to directly attack cities and storm their walls. Even when direct assaults were made with cannons, it was usually by focusing on the gates rather than the walls. There were instances where cannons were used against walled fortifications, such as by
Koxinga, but only in the case of small villages. During Koxinga's career, there is only one recorded case of capturing a settlement by bombarding its walls: the siege of Taizhou in 1658. In 1662, the Dutch found that bombarding the walls of a town in
Fujian Province had no effect and they focused on the gates instead just as in Chinese warfare. In 1841, a 74-gun British warship bombarded a Chinese coastal fort near Guangzhou and found that it was "almost impervious to the efforts of horizontal fire." In fact
twentieth century explosive shells had some difficulty creating a breach in tamped earthen walls.
Bastions and star forts ,
Italy, an example of a
Venetian star fort As a response to gunpowder artillery, European fortifications began displaying architectural principles such as lower and thicker walls in the mid-1400s. Cannon towers were built with artillery rooms where cannons could discharge fire from slits in the walls. However, this proved problematic as the slow rate of fire, reverberating concussions, and noxious fumes produced greatly hindered defenders. Gun towers also limited the size and number of cannon placements because the rooms could only be built so big. Notable surviving artillery towers include a seven layer defensive structure built in 1480 at
Fougères in
Brittany, and a four layer tower built in 1479 at Querfurth in Saxony. The star fort, also known as the bastion fort,
trace italienne, or renaissance fortress, was a style of fortification that became popular in Europe during the 16th century. The bastion and star fort was developed in Italy, where the Florentine engineer
Giuliano da Sangallo (1445–1516) compiled a comprehensive defensive plan using the geometric
bastion and full
trace italienne that became widespread in Europe. The main distinguishing features of the star fort were its angle bastions, each placed to support their neighbor with lethal crossfire, covering all angles, making them extremely difficult to engage with and attack. Angle bastions consisted of two faces and two flanks. Artillery positions positioned at the flanks could fire parallel into the opposite bastion's line of fire, thus providing two lines of cover fire against an armed assault on the wall, and preventing mining parties from finding refuge. Meanwhile, artillery positioned on the bastion platform could fire frontally from the two faces, also providing overlapping fire with the opposite bastion. Overlapping mutually supporting defensive fire was the greatest advantage enjoyed by the star fort. As a result, sieges lasted longer and became more difficult affairs. By the 1530s the bastion fort had become the dominant defensive structure in Italy. Outside Europe, the star fort became an "engine of European expansion," and acted as a force multiplier so that small European garrisons could hold out against numerically superior forces. Wherever star forts were erected the natives experienced great difficulty in uprooting European invaders. In China,
Sun Yuanhua advocated for the construction of angled
bastion forts in his
Xifashenji so that their cannons could better support each other. The officials Han Yun and Han Lin noted that cannons on square forts could not support each side as well as bastion forts. Their efforts to construct bastion forts, and their results, were limited. Ma Weicheng built two bastion forts in his home county, which helped fend off a
Qing incursion in 1638. By 1641, there were ten bastion forts in the county. Before bastion forts could spread any 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.
Decline ,
Nanjing In the wake of city growth and the ensuing change of defensive strategy, focusing more on the defense of
forts around cities, many city walls were demolished. Also, the invention of gunpowder rendered walls less effective, as siege cannons could then be used to blast through walls, allowing armies to simply march through. Today, the presence of former city fortifications can often only be deduced from the presence of ditches,
ring roads or parks. Furthermore, some street names hint at the presence of fortifications in times past, for example when words such as "wall" or "glacis" occur. In the 19th century, less emphasis was placed on preserving the fortifications for the sake of their architectural or historical value on the one hand, complete fortifications were restored (
Carcassonne), on the other hand many structures were demolished in an effort to modernize the cities. One exception to this is the "monument preservation" law by the Bavarian King
Ludwig I of Bavaria, which led to the nearly complete preservation of many monuments such as the
Rothenburg ob der Tauber,
Nördlingen,
Berching and
Dinkelsbühl. The countless small fortified towns in the
Franconia region were also preserved as a consequence of this edict.
Modern era Walls and fortified wall structures were still built in the modern era. They did not, however, have the original purpose of being a structure able to resist a prolonged siege or bombardment. Modern examples of defensive walls include: • Berlin's city wall from the 1730s to the 1860s was partially made of wood. Its primary purpose was to enable the city to impose tolls on goods and, secondarily, also served to prevent the desertion of soldiers from the garrison in Berlin. • The
Berlin Wall (1961 to 1989) was built around
West Berlin by the
German Democratic Republic to prevent its citizens from fleeing to the
West German exclave. • The
Korean Demilitarized Zone that divides North Korea and South Korea near the 38th parallel north. • The Nicosia Wall along the
Green Line divides North and South Cyprus. • In the 20th century and after, many enclaved Jewish settlements in Israeli occupied territory in the West Bank were and are surrounded by fortified walls •
Mexico–United States barrier, a wall advocated by U.S. President
Donald Trump for the
Mexico–United States border to prevent illegal immigration, drug smuggling, human trafficking, and entry of potential terrorists •
Belfast,
Northern Ireland by the "
peace lines". •
Gaza–Israel barrier, first constructed by Israel in 1971 as a security barrier and has been rebuilt and upgraded since. The barrier has been effective in preventing terrorists and suicide bombers from entering Israel from Gaza. •
Gated communities are modern residential neighborhoods where access is controlled, often prohibiting through-travelers or non-residents via a wall and guards Additionally, in some countries, different embassies may be grouped together in a single "embassy district", enclosed by a fortified complex with walls and towersthis usually occurs in regions where the embassies run a high risk of being target of attacks. An early example of such a compound was the
Legation Quarter in
Beijing in the late 19th and early 20th centuries. Most of these modern city walls are made of steel and concrete. Vertical concrete plates are put together so as to allow the least space in between them, and are rooted firmly in the ground. The top of the wall is often protruding and beset with
barbed wire in order to make climbing them more difficult. These walls are usually built in straight lines and covered by watchtowers at the corners. Double walls with an interstitial "zone of fire", as the former Berlin Wall had, are now rare. In September 2014, Ukraine announced the construction of the "European Rampart" alongside its
border with Russia to be able to successfully apply for a visa-free movement with the European Union. == Composition ==