The art and science of fortification is older than the invention of writing, dating back to the Neolithic era.  When humans began to live in larger communities, they began to safeguard their loved ones and material wealth through the means  of rudimentary fortifications like earthen ramparts, wooden palisades, and ditches usually located in defensible positions on hills are next to ravines. With the rise of civilization came the rise of cities,and the introduction of urban fortifications in Mesopotamia, Egypt, Anatolia, and eventually the greater Near East. Early urban fortifications took the form of circuit walls often attached or surrounding a citadel, punctuated with numerous gates for entry into the city.  Walls and forts were constructed with readily available material, depending on the region (sun-dried or fired bricks or hard stone), with the type of material used dictating the width and height of these fortifications.  Eventually, additional defensive features were added like battlements, bastions, balconies (parapets or machicolations) and stronger gate houses. Battlements were constructed at the top of the wall as a space for sentries and as a place for defenders to protect the wall. Battlements included a walkway with access to towers and turrets (and sometimes stairways to lower floors or the ground-level) and were protected by a sawtooth defensive work or crenellation projecting upwards from the outer wall. Crenellation consisted of merlons (a narrow protective wall set at intervals from which a defender could seek protection and reload his bow or sling) and crenels (the open gap between the merlons), while bastions were a projecting part of a fortification built at an angle to the line of a wall to allow defensive fire in several directions. Another defensive feature of battlements consisted of parapets and machicolations through or over which stones, or other objects, could be dropped on attackers at the base of a defensive wall. And finally, gatehouse design also improved with the addition of different forms of barriers to bar entry during siege (dry or water-filled moats, drawbridges, iron reinforced wooden doors, and bastions for covering fire). Many of these defensive features are associated with later medieval urban and castle fortifications, but their origins date to the Bronze and early Iron ages in Western Civilization.

At right: A modern reimagining of the curtain and interior walls of the Bronze Age Hittite capital of Hattusa in central Turkey.  Source: Amazing Planet. In the Public Domain. Click to enlarge.

Prehistoric Fortifications

The first evidence of urban fortification dates back to the city of Jericho in West Bank in Palestine around the tenth millennium BCE, perhaps the longest continuously inhabited city in the world. Jericho’s first city wall was elevn feet high, and over six feet thick with a stone tower that reached a height of twenty-eight feet. over the millennia, Jericho would construct a second curtain wall to protect the city, one with sixteen square towers and a double gate system protected by two gate houses, and interior and exterior, each protected by large square towers.  Archaeologists estimate that the walls of Jericho have been reconstructed at least fifteen times during its 11,000-year history.  Another early example of urban fortification can be seen at the prehistoric site at Çatal Huyuk (inhabited between c.7100 and c.6300 BCE) in what is now south-central Anatolia (in modern Türkiye). Here, humans built a fortified settlement with interconnected houses that shared common walls built on a standardized rectangular plan with access into each house by latter through a hole in the roof. In fact, there are no external entryways on the outer walls around the entire structure, creating a de facto defensive wall.  Farther east in Mesopotamia (Greek for “the land between the rivers,” referring to the Tigris and Euphrates), the first walled cities were erected around the first urban centers around 4500 BCE.  These early city walls was constructed to include gates and watchtowers, with the city’s outer perimeter first protected by a water filled moat.  Later, walls were added as these first cities evolved into city-states, and formed the first of the Mesopotamian civilizations, the Sumerian civilization (c.3000 –c.2334 BCE) centered around the urban centers of Eridu, Bad-tibura, Shuruppak, Uruk, Sippar, and Ur, with Uruk probably the first of these walled cities, but Ur the most famous. 

At right: Model of the neolithic settlement (7300 BC) of Çatal Huyuk (Turkey), showing no external doors. Museum for Prehistory in Thuringia. Source: Wikipedia; in the Public Domain. This file is licensed under the Creative Commons  Attribution-Share Alike 4.0 International license. 

The Early Mesopotamian Walled City: Heart of the Sumerian City-State

The outer wall encircling Ur was in the shape of an oval and measured approximately 1,300 yards long by 875 yards wide, with its longer axis lying north to south. This outer wall was thick, eighty to 110 feet thick at its base, because southern Mesopotamia lacked either building stones or sufficient fuel to bake large brick from which to construct freestanding walls, requiring the thickness of earthen walls at the base to be at least one third the height of the wall, with some walls up to two thirds the height. These walls resembled ramparts made of adobe brick with a vertical outward face of thin baked bricks. However, Sumerian military engineers increased the defensive qualities of these lower squatter walls by building balconies and towers from which defenders could shoot down at the base of the fortification and along the curtain wall. By placing the towers no further apart than the effective range of the bow, sling, or spear (about ninety feet), these Sumerian architects not only assured that there would be no dead space between the towers, but also made the full length of the wall subject to flanking fire from two directions. These engineers also designed walls on a zigzag pattern or breaking a curve into a series of right angles in order to increase flanking fire and make the walls more defensible.  After the invention of the wheeled war wagon, city gates had to be wide enough in the entrance accessible enough to allow these war machines to move in and out of the city. Small gates evolved into double door gates, which were weak at the center. Heavy wooden beam inserted horizontally behind the double doors greatly strengthen them. Frequently, metal plating covered wooden doors to make them resistant to fire. Entrance ways bristled with bastions, towers, and balconies to provide maximum protection at the weakest point of any wall, the gate.

Akkadian and Babylonian Walled Cities

The next great Mesopotamian civilization was founded by Sargon of Akkad (“the Great,” r.2334-2279 BCE) who forged the first empire in world history, uniting much of Mesopotamia under his imperium with direct territory or tributaries stretching from the “Upper Sea” (the Mediterranean) to the “Lower Sea” (the Persian Gulf).  However, the location of his capital, Akkad, has not been definitively located. However, scholars do know the location of the next great imperial capital in Mesopotamia, the walled city of Babylon, a city so opulent that it becomes a namesake for the Old Babylonian Empire. Under its first great king, Hammurabi “the Lawgiver” (r.1792-1750 BCE) the city was walled for the first time, although little remains of this first urban fortification. He used his newly walled capital as a base of operations to create another Mesopotamian empire, defeating the wall defenses of his enemies. Hammurabi’s empire quickly fell apart shortly after his death, and Babylon was sacked by the Hittites, and occupied and renamed by Kassites, however, Babylon’s strategic location along the Euphrates River would ensure its longevity as an important trading center for millennia and will later be the namesake for a second Mesopotamian state, the early Iron Age Neo-Babylonian or Chaldean Empire. 

Early Egyptian Fortifications

Perhaps the earliest evidence of fortifications and siegecraft comes from the famous Narmer Palette (c.3100 BCE) illustrating the Egyptian King Narmer (also known as Menes) from Upper Egypt besieging fortifications in Lower Egypt. Here, the palette shows sophisticated urban defenses with walls studded with bastions. Additionally, there is some speculation that the depiction of a bull attacking city walls is Narmer in animal form, perhaps the first pictorial example of siege warfare in history. By the time of Egypt’s Middle Kingdom (c.2055-c.1650 BCE), the art of fortification reaches an even higher level. An Egyptian wall painting at Beni Hasan shows a complete defensive system featuring high walls with battlements and machicolated balconies from which arrows provided flanking fire and access to besiegers attacking the base of the wall. Paintings also clearly show the placement of a sloped bank or glacis at the foot of wall to make the approach to the wall even more difficult. The fortress at Buhen, just north of the second cataract in Upper Egypt along Egypt’s Nubian frontier, is another elaborate fortification protecting the west bank of the Nile River. Built during the reign of Pharaoh Senusret II (r.1897-1878 BCE), Buhen is the northernmost of four fortress originally built by Senusret within signaling distance of one another to protect the southern frontier. In the New Kingdom period (c.1550-c.1070 BCE), other forts were constructed, to eventually include Buhen, Mirgissa, Shalfak, Uronarti, Askut, Dabenarti, Semna, and Kumma. The walls of Buhen encompassed an area of 3.2 acres (15,500 square yards) for a town laid out in a grid system. Buhen was protected by a main wall crafted out of rough stone over sixteen feet thick, and over thirty feet high. It had square bastions every fifteen feet, and large towers protruding from each corner of the square shaped fort. A lower wall protected the main wall. The lower wall also had bastions located every thirty feet. Both the wall and the bastions had crenelations skillfully placed to provide a wide angle of supporting fire. A dry moat twenty-eight feet wide and twenty feet deep ran around the foot of the lower wall, with yet another lower wall circling the outside edge of the moat, with its face strengthened by an earthen glacis. Bridging the moat was done by a drawbridge connected to a sophisticated gatehouse consisting of two large towers forty-five feet high and outer works stretching from the main gate to the outer wall, allowing archers to control fire along parallel approaches. The outer curtain walls protected an inner fortress containing a Temple to Horus. The fortress housed 1,000 infantry and 300 archers and their families.  The fortress at Semna has similar features, although it was built in an L shape next to the Nile.

At right: A color drawing of the ancient Egyptian fortification at Buhen based on archaeological surveys. Source: Wikipedia. In the Public Domain. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.

Bronze Age Anatolian Fortifications: The Walled Hittite capital of Hattusa

Centered in Anatolia (Asia Minor) with its capital at Hattusa, the Hittites Empire (c.1600-c.1178 BCE) was the first significant Indo-European state in world history but borrowed heavily from Mesopotamian culture.  Hattusa itself was protected by a complicated system of walls, skillfully adapted to the contours of its hilly site and making the Hittite capital the apex of late Bronze Age fortification. Hattusa was surrounded by approximately 5.6 miles of double walls encompassing some 445 acres (180 hectares) of urban space, with the walls protected by some 300 towers (Hittite fortifications contained more towers than their contemporary near Eastern or Aegean counterparts).  The entire city was situated on two elevations, an upper city (which was larger and contained the citadel) and a lower city.  Unlike Mesopotamian architects, who preferred to avoid circular designs in favor of sharp angles, Hittite military engineers preferred making walls more circular that rectangular. Circular walls for more difficult to cover with flanking fire, but corners were more vulnerable to undermining. The 

main walls were of the casemate type (double walls with a narrow space in between filled with rubble, a standard building design of later classical and medieval fortifications). A lower

 outer wall, about twenty feet in front, protected the main wall which rose to perhaps twenty feet in height, protected again by taller towers along its length. Narrow underground tunnels (posterns) provided a means for staging surprise sorties against besiegers, with the southern wall hiding ten of these tunnels (the side opposite the most likely direction of attack). Interior walls divided the city into sections, so an enemy breaking through gained access to only part of the city. Hattusa also provide some of the finest examples of fortified gates. An inner citadel stood on a hill on a rocky spur, offering a last line of defense.  Together, the urban defenses at Hattusa were some of the most sophisticated in the ancient world, with many features unique features that will become common in the later Classical and Medieval fortifications. Hattusa was added to the UNESCO World Heritage Site list in 1986.

At right: Ḫattuša was the capital of the Hittite Empire in the late Bronze Age. Its ruins lie near modern Boğazkale, Turkey, within the great loop of the Kızılırmak River (Hittite: Marashantiya; Greek: Halys).  For perspective on size and scale, note the white SUV. Source: The Archaeologist. In the Public Domain. Click to enlarge.

Neo Assyrian Fortifications

Centered on the three major cities of Ashur, Nimrud, and Nineveh on the upper Tigris River in what is now northwestern Iraq, the Bronze Age Assyrian Empire (c.2025-912 BCE) and Early Iron Age Neo Assyrian Empire (c.850-612 BCE) was cursed with a dearth of natural resources and few natural barriers to keep out enemy invasions.  The region of Assyria lacked wood for constructing forts, temples and dams, building stone for walls and castles and iron ore deposits to forge weapons, however, Assyrian kings expanded their territory to secure many of these strategic resources and built large fortified cities and fortresses. The first of these great cities, Ashur, was built early in Assyrian history in a defensible position on a rocky limestone cliff eighty feet above the Tigris River. This walled city served as the capital and important economic nexus for the Old Assyrian Empire before its contraction during the chaos associated with the late Bronze Age collapse. Empire building began again in the mid-ninth century BCE under Ashurnasirpal II (r.884-859 BCE), the Ashur as his capital. Later Assyrian kings would build other capitals at Nimrud, Dur-Sharrukin, and Nineveh. At Nimrud, archaeologists have located fifty-eight towers along the north wall, while at Nineveh there are remains of three walls, the lower part being of stone, and the upper being of sun-dried bricks. At Dur-Sharrukin there are the remains of a wall, still forty feet high, built of blocks of stone three to four feet thick. Tiers of walls enclose a great tower of keep in the center of the enclosure, with arched gateways flanked by square towers. At Nimrud, Nineveh, and Assur sophisticated battlements have been unearthed with overhanging parapets and battlements similar to later medieval machicolations. Early masters of Iron Age siegecraft, the Neo Assyrians incorporated the best defenses of their enemies into their own military architecture, however, it was not enough to save their capitals from the wrath of their harshly treated subject peoples. In 612 BCE, Ashur and Nineveh were successfully sieged, stormed, and razed by an alliance of Chaldeans, Medes, Persians, and Scythians, ending the first Iron Age Empire in the Near East.  

Chaldean Fortification: The New Walls of Babylon

After the fall of the Neo-Assyrian Empire, its most powerful client kingdom, the Chaldeans (also known as the Neo-Babylonians) built a short-lived empire centered in Mesopotamia. Their most famous king, Nebuchadnezzar II (r.604-562 BCE) renovated the ancient city of Babylon, making it one of the best protected cities in the ancient world.  Nebuchadnezzar used the water of the Euphrates River, which bisected the city, to construct a system of canals that served as moats in defense of the city. Moreover, modern excavations have revealed no less than five walls, three composing the outer walls and two composing the inner walls. The inner wall also had at regular intervals towers, which may have been similar to those along the outer wall. The “Father of Western History” Herodotus (484-425 BCE) claimed that "Babylon surpasses in wonder any city in the known world" and specifically praised the city’s urban fortifications, stating they were fifty-six miles long, eighty feet thick, and 320 feet high. Here, Herodotus clearly exaggerated the size and extent of Babylon’s walls; however, other ancient writers also commented on the magnificence of its urban defenses.  The actual dimensions of the city are much smaller, at 3,800 yards by 5,400 yards, or 2.2 miles by three miles, with an outer defense made up of a wide and deep moat.  Babylon’s curtain walls were made of bricks, either baked in kilns or sun dried, before laid in a bitumen cement, with occasional layers of reeds placed between the layers.  The curtain walls were punctuated by low towers, rising above the battlements to a height of some ten or fifteen feet, and probably serving as guardrooms for the defenders. Classical sources indicate 250 towers altogether, with many of the towers located on the western face of the city where the wall ran along the marshes. They were probably angular, not round, and, instead of extending through the whole thickness of the wall, they were placed along its outer and inner edge, tower facing tower, with a wide space between them-" enough," Herodotus says, "for a four-horse chariot to turn in. The wall did not depend on them for its strength, but on its own height and thickness, which were such as to render scaling and mining equally hopeless." The Ishtar Gate, one of the eight gates of the inner city of Babylon, survives from the reign of Nebuchadnezzar. The Ishtar Gate was constructed circa 575 BCE on the north side of the city as the gateway to the main thoroughfare through the Chaldean capital. The gate is forty-seven feet high and thirty-two feet wide and finished in blue glazed bricks with majestic liens, bowls, and dragons itched in bas relief greeting visitors as they pass through the walls.  Today, a small portion of this resplendent gate is on display in the Pergamon Museum in Berlin.

Persian Fortifications and the Royal Road

The Achaemenid Persians under Great Kings Cyrus II (“the Great,” r.559-530 BCE), Cambyses I (r.530-522 BCE) and Darius I (522-486 BCE) quickly forged a large Near Eastern empire, stretching from the Balkans and Libya in the west to Central Asia and the Indus River Valley in the east.  However, the Persians were not great urban fortification builders themselves, instead inheriting numerous walled cities from their defeated foes (Medians, Lydians, Chaldeans, Egyptians) and constructing a ceremonial capital at Persepolis, the greatest palace complex in the world at the time of its construction, and one infamously destroyed by Alexander the Great in 330 BCE. The Achaemenids ruled from four different capitals located across the empire: Pasargadae (the original Persian capital) and Ecbatana (the original Median capital), and Babylon and Susa, which both had history stretching back to the Bronze Age. Pasargadae’s citadel watched over the mausoleum of Cyrus II, but the city was soon overshadowed by Susa and Persepolis due to new palace construction by Cambyses and Darius. Located in what is today northern Iran, Ecbatana was described by Herodotus as an impressive ringed city of various colors:

"The Medes built the city now called Ecbatana, the walls of which are of great size and strength, rising in circles one within the other. The plan of the place is that each of the walls should out top the one beyond it by its battlements. The nature of the ground, which is a gentle hill, favors this arrangements in some degree but it is mainly effected by art. The number of the circles is seven, the royal palace and the treasuries standing within the last. The circuit of the outer wall is very nearly the same with that of Athens. On this wall the battlements are white, of the next black, the third scarlet, the fourth blue, the fifth orange; all these colored with paint. The last two have their battlements coated respectively with silver and gold…."

At right: Full-size sections of reconstructed walls at Babylon in modern Iraq. Source: Wikipedia. In the Public Domain. This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Click to enlarge.

Modern scholars are not certain whether Herodotus is describing a ziggurat, although Neo-Assyrian stone reliefs indicate the use of multiple concentric walls in the city’s defense. Cyrus II captured the Elamite capital of Susa in 540 BCE and Chaldean capital of Babylon in 539 BCE, the latter only decades after Nebuchadnezzar’s revitalization of the city.  All four of these capitals were in the interior of the largest Near Eastern empire to date (three million square miles of territory with fifty million inhabitants), allowing the Achaemenids to craft a grand strategy which emphasized mobility and maneuver over positional warfare. The Persians used their financial resources to build the first large international highway system in world history, referred to as the Persian Royal Road. In fact, Pasargadae, Ecbatana, Babylon and Susa were connected by part of this highway system. The main part of this highway stretch from Sardis in western Anatolia to Susa in southern Persia, a distance of 1,677 miles, with additional roads crossing the Zagros Mountains into Persia itself connecting Pasargadae and nearby Persepolis. There was an additional main highway that stretched from the city of Opis on the Tigris River across the Zagros Mountains to Ecbatana. Mounted couriers could travel the distance between Sardis and Susa in just seven days, utilizing 112 postal stations, maintaining fresh horses. The same distance took ninety days to traverse on foot.  And like highway systems of every age (Roman Limes, Nazi Germany’s Autobahn, and the American Interstate system), the Royal Road facilitated and protected trade between regions during peacetime and provided an efficient means to project force to far flung borders during war (i.e., the Persian Wars with Greece) or quell internal rebellion.

The history of Near Eastern fortification parallels the history of human civilization in this region of the world.  Built at great expense, urban fortifications represent the power, stability, and wealth of a civilization, expressed through their sheer magnitude, design, and geometry.  With the first Neolithic fortifications at Jericho and Çatal Huyuk, through the rise of Bronze Age and early Iron Age Mesopotamian city states and regional empire building across the Near East, the art and science of urban fortifications grew more sophisticated as the art and science of siegecraft advanced. New defensive techniques were implemented to defeat a besiegers’ main objectives: approaching the fortification, going over the fortification, going through the fortification, or going under the fortification.  This resulted in an offensive-defensive cycle of weapon and military architectural innovation which would continue throughout the Classical and Medieval eras and into the twenty-first century.

Suggested Readings:

Primary sources

Strassler, Robert B. ed. The Landmark Herodotus: The Histories. Anchor, 2009.

Secondary sources

Cotterall, Arthur. Where War Began: A Military History of the Middle East from the Birth of Civilization to Alexander the Great and the Romans. Stackpole Books, 2022.

Fales, Frederick. War in the Assyrian Empire. Blackwell, 2016.

Farrokh, Kaveh. Shadows in the Desert: Ancient Persia at War. Osprey, 2009.

Nossov, Konstantin. Hittite Fortifications c. 1650-700 BC. Bloomsbury Publishing, 2012.

Vogel, Carola. The Fortifications of Ancient Egypt, 3000-1780 BC. Osprey Publishing, 2010.