The Indus Valley Civilization: The First Planned Cities

The Indus Valley Civilization was the largest of the four ancient civilizations of the Old World — larger in area than Mesopotamia and Egypt combined. It flourished between about 2600 and 1900 BCE, at its height stretching across more than a million square kilometers of what is now Pakistan and northwest India. The two great cities of the civilization, Harappa and Mohenjo-Daro, were among the largest in the ancient world, with populations of perhaps 40,000 each. Their streets were laid out on a regular grid, their houses were built of standardized fired bricks, and their sewers, wells, and bathing platforms were more sophisticated than those of contemporary Egypt or Mesopotamia.

The civilization is also the most mysterious of the four. Its script, found on thousands of seals, has not been deciphered. Its political system is unknown. Its religion is mostly unknown. After about six hundred years of urban life, the Indus cities were abandoned, and the civilization that built them disappeared, leaving behind only the ruins, the seals, and a long list of questions.

This cluster page is a guided tour of the Indus civilization: its cities, its trade, its script, its religion, and the questions that still surround it. It links out to the Vedic Period, Ashoka the Great, and the Silk Road.

The Geography of the Indus

The Indus River is one of the great rivers of the world, rising in the Himalayas and flowing southwest through modern Pakistan to the Arabian Sea. The Indus Valley is hot, dry in places, and watered by a complex system of rivers that has changed course many times. The civilization of the Indus grew up along the Indus and its sister rivers, particularly the now-dry Ghaggar-Hakra River in the Indian Thar Desert, the Ravi, the Chenab, and the Jhelum.

The Indus Valley had many of the same advantages as the Nile Valley of Egypt and the Tigris-Euphrates Valley of Mesopotamia. The annual floods of the rivers deposited rich silt, the climate allowed for two crops a year, and the long river system provided easy transportation.

The Discovery of the Civilization

The Indus civilization was not discovered until the twentieth century. The ruins of Harappa were first identified by the British engineers who were laying the railway in 1856. The site of Mohenjo-Daro was identified in 1922 by the Indian archaeologist R. D. Banerji. The civilization was then excavated by a succession of British and Indian archaeologists, including Mortimer Wheeler, John Marshall, and (most importantly) Mortimer Wheeler’s successor, the Indian archaeologist M. S. Vatsa.

The script of the Indus civilization has not been deciphered. The seals — square soapstone stamps with animal figures and short inscriptions — were known from the beginning, but no one has been able to read them with confidence. Several modern scholars have claimed to have made progress, but none of the readings has been generally accepted.

The Cities

The two great cities of the Indus civilization, Harappa and Mohenjo-Daro, were discovered in the 1920s. Both were built on a regular grid plan, with streets crossing at right angles and a complex system of covered drains running along the side of every major street. The houses were built of standardized fired bricks, with thick walls to keep out the heat, and most had an inner courtyard, a private well, and a bathing platform. Some houses were two or three stories tall.

The cities were laid out in a hierarchy of sizes. Mohenjo-Daro and Harappa were the largest. Below them were a series of medium-sized cities, including Dholavira, Kalibangan, and Lothal. Below them were hundreds of smaller towns and villages. The total population of the civilization at its height is estimated at one to five million people.

The cities had no palaces, no temples, and no clear royal tombs. The absence of palaces and royal tombs is one of the great puzzles of the civilization. Either the Indus civilization was ruled by a small, austere ruling class that did not leave obvious monuments, or it was a relatively egalitarian society without a single dominant ruler.

The Economy

The Indus economy was based on agriculture, with wheat, barley, peas, sesame, and cotton as the main crops. The civilization was also a major trading partner of Mesopotamia. Indus seals have been found in Mesopotamian sites as far away as Ur, and the Indus civilization imported lapis lazuli from Afghanistan, copper from Oman, and carnelian from Gujarat.

The Indus civilization is the first in the world to produce cotton, and the first to develop a system of standardized weights and measures. The famous “Indus weight” was a small, polished cube of black stone, used throughout the civilization for the weighing of goods.

The Script

The Indus script is one of the great unsolved puzzles of the ancient world. About 400 signs have been identified, and the inscriptions are short — usually no more than five signs. The most common theory is that the script was used for the names of individuals, places, and goods, but the lack of a bilingual inscription (like the Rosetta Stone for Egypt) has made decipherment impossible.

The Religion

The religion of the Indus civilization is mostly unknown. The most common artistic motifs on the seals are animals — the bull, the elephant, the rhinoceros, the tiger, the crocodile, and a mythical one-horned beast sometimes called the “unicorn seal.” A few seal images have been interpreted as showing figures in yogic postures, which some scholars have used to argue for an early origin of Hindu or proto-Hindu religious practices.

Some Indus figures have been tentatively identified as “proto-Shiva” — a horned figure surrounded by animals, sometimes called the Pashupati (“lord of the animals”) because of the seal from Mohenjo-Daro that shows him surrounded by a tiger, an elephant, a rhinoceros, and a buffalo. The identification is highly controversial.

The Decline

The Indus civilization collapsed between about 1900 and 1300 BCE. The causes are still debated. Theories include climate change, a shift in the course of the Indus, deforestation, soil exhaustion, foreign invasion, and some combination of these factors. The cities were gradually abandoned, the script was forgotten, and the civilization that built them disappeared.

The Indus civilization was followed, after a long gap, by the Vedic Period, the Bronze Age civilization of the Indian subcontinent that produced the Vedas, the foundational texts of Hinduism. The Indus civilization is, in many ways, the lost civilization of the ancient world: large, sophisticated, urban, and almost entirely unknown to us.

The Legacy of the Indus

The Indus civilization’s most lasting legacy is the fact that the modern nations of Pakistan and India are both heavily influenced by the civilization that built the cities. The Indus Valley Civilization is celebrated in both countries as the foundation of South Asian civilization. The recent DNA studies of the people of the Indus Valley have shown remarkable continuity between the ancient and modern populations of the region, suggesting that the modern people of the Indus Valley are, to a significant extent, the direct descendants of the civilization that built the cities.