The Indus Valley Civilization, also called the Indus Civilization, was an ancient society in the northwestern parts of South Asia. It existed from about 3300 BCE to 1300 BCE, with its most developed stage from 2600 BCE to 1900 BCE. Along with ancient Egypt and Mesopotamia, it was one of the three major early civilizations in the Near East and South Asia. Of these, the Indus Civilization covered the largest area, including much of modern Pakistan, parts of northwestern India, and northeast Afghanistan. It thrived in the fertile land near the Indus River, which runs through Pakistan, and along a system of rivers that once flowed near the Ghaggar-Hakra, a seasonal river in northwest India and eastern Pakistan.
The term "Harappan" is also used for the Indus Civilization, named after Harappa, the first site discovered in the early 1900s in what was then the Punjab province of British India, now Punjab, Pakistan. The discovery of Harappa and Mohenjo-daro followed efforts that began after the Archaeological Survey of India was established in 1861. Earlier and later cultures in the same area were called Early Harappan and Late Harappan. The Early Harappan cultures developed from Neolithic societies, the best-known of which is named after Mehrgarh in Balochistan, Pakistan. The Harappan Civilization is sometimes called Mature Harappan to separate it from earlier cultures.
The cities of the Indus Civilization were known for their well-planned layouts, brick homes, advanced drainage and water systems, large buildings that were not homes, and skilled craftsmanship in making tools and metal objects. Mohenjo-daro and Harappa likely each had between 30,000 and 60,000 people, and the entire civilization may have had between 1 million and 5 million people at its peak. A gradual drying of the region around 3000 BCE may have started the process of urban development. Over time, the reduced water supply likely led to the civilization’s decline and the movement of its people eastward.
More than 1,000 Mature Harappan sites have been found, with nearly 100 studied in detail. Five major cities include Mohenjo-daro in the lower Indus Valley (a UNESCO World Heritage Site since 1980), Harappa in western Punjab, Ganeriwala in the Cholistan Desert, Dholavira in western Gujarat (a UNESCO World Heritage Site since 2021), and Rakhigarhi in Haryana. The Harappan language has not been directly recorded, and its connection to other language groups is unclear because the Indus script has not been fully understood. Some scholars suggest it may be related to the Dravidian or Elamo-Dravidian language families.
Etymology
The Indus Valley Civilization is named after the Indus River system. The first places where this civilization was discovered and studied were located in the fertile areas near the river.
In archaeology, it is common to name civilizations after their first discovered site. The Indus Valley Civilization is sometimes called the Harappan Civilization, named after Harappa, the first site found in the 1920s. This name is often used by the Archaeological Survey of India since India became independent in 1947.
The term "Ghaggar-Hakra" is now frequently used to describe the Indus Valley Civilization because many of its sites were found along the Ghaggar-Hakra River in northwest India and eastern Pakistan. Other names, such as "Indus-Sarasvati Civilization" and "Sindhu-Saraswati Civilization," have also been used by some scholars. These names are based on the belief that the Ghaggar-Hakra River was the same as the Sarasvati River mentioned in the Rigveda, an ancient Sanskrit text written around 2000 BCE. However, these names are not directly connected to the main period of the Indus Valley Civilization.
Recent scientific studies suggest that the Ghaggar-Hakra River was once a system of rivers that flowed year-round due to monsoon rains. However, around 4,000 years ago, these rivers became seasonal, meaning they only flowed during certain times of the year. This change may have contributed to the decline of the civilization.
Extent
The Indus Valley Civilization existed at about the same time as other ancient river civilizations, such as Ancient Egypt along the Nile, Mesopotamia near the Euphrates and Tigris rivers, and China in the areas of the Yellow River and Yangtze. During its mature phase, the Indus Valley Civilization covered a larger area than these other civilizations. Its core region stretched about 1,500 kilometers (900 miles) up the fertile land of the Indus River and its tributaries. In addition, a much larger area—up to ten times the size of the core region—was influenced by the Indus Valley Civilization in terms of culture and economy.
Agriculture began in Balochistan, near the edges of the Indus River’s fertile land, around 6500 BCE. Over the next few thousand years, people started to settle in the Indus River plains, leading to the growth of villages and cities. This more organized way of life caused the birth rate to increase. Large cities like Mohenjo-daro and Harappa likely had between 30,000 and 60,000 people. During the civilization’s peak, the population of the Indian subcontinent may have reached between 4 and 6 million people. However, living in close quarters with domesticated animals increased the spread of diseases, which raised the death rate. Some estimates suggest the Indus Valley Civilization’s population at its peak was between 1 and 5 million.
At its height, the Indus Valley Civilization stretched from Balochistan in the west to western Uttar Pradesh in the east, from northeastern Afghanistan in the north to Gujarat in the south. The most sites were found in the Punjab region, Gujarat, Haryana, Rajasthan, Uttar Pradesh, Jammu and Kashmir, Sindh, and Balochistan. Coastal settlements ranged from Sutkagan Dor in western Baluchistan to Lothal in Gujarat. The northernmost site was at Shortugai on the Oxus River in Afghanistan. Other sites included Manda on the Beas River in Jammu, and Alamgirpur on the Hindon River near Delhi. The southernmost site was Daimabad in Maharashtra. Most Indus Valley sites were located near rivers, but some were on ancient coastlines, such as Balakot, and on islands, like Dholavira.
Discovery and history of excavation
Three other important scholars who helped study Mohenjo-daro were Mr. R. D. Banerji, who first recognized the site's great age, and his successors, Messrs. M.S. Vats and K.N. Dikshit. These people worked hard to dig at the site, but they faced many challenges during the first few years of their work.
The first modern records of the ruins of the Indus civilization were made by Charles Masson, who had left his job in the East India Company’s army. In 1829, Masson traveled through the Punjab region, sharing information with the Company in exchange for protection from punishment. As part of this agreement, he was required to give the Company any historical items he found during his travels. Masson studied ancient history, especially the campaigns of Alexander the Great, and chose to visit places that had been part of those campaigns. His most important discovery was Harappa, a large city of the Indus civilization near the Ravi River. Masson wrote detailed notes and made drawings of the site’s artifacts, many of which were buried. In 1842, he included his observations about Harappa in a book. He incorrectly believed the ruins were from the time of Alexander the Great. Masson noted the site’s large size and the mounds of dirt and stone that had formed over time.
Two years later, the East India Company sent Alexander Burnes to explore the Indus River for possible use by the army. Burnes visited Harappa and noticed the ancient bricks used in the site’s buildings. However, he also saw that local people had taken bricks from the site.
After the British took control of the Punjab in 1848–49, Harappa’s bricks were taken even more heavily. Many were used to build railway tracks between Multan and Lahore in the mid-1850s.
In 1861, three years after the East India Company was dissolved and Britain took direct control of India, the Archaeological Survey of India (ASI) was created to organize archaeological work. Alexander Cunningham, the first director of the ASI, visited Harappa in 1853 and saw its large brick walls. He returned later to study the site, but much of the top layer had been removed. Though he hoped to prove Harappa was a lost Buddhist city mentioned by a Chinese traveler, he could not find proof. Instead, he published his findings in 1875, including the discovery of a Harappan seal with an unknown script.
Archaeological work at Harappa slowed until 1904, when Lord Curzon passed a law to protect ancient sites and appointed John Marshall to lead the ASI. Marshall sent Hiranand Sastri to study Harappa, who later reported that the site was not Buddhist and much older. Marshall then ordered ASI archaeologist Daya Ram Sahni to dig at the site’s mounds.
Further south, in the Indus River’s Sind province, the site of Mohenjo-daro remained mostly untouched. Marshall assigned several ASI officers to study the site, including D. R. Bhandarkar (1911), R. D. Banerji (1919, 1922–1923), and M. S. Vats (1924). In 1923, Banerji wrote to Marshall about Mohenjo-daro, suggesting it was very old and noting similarities between its artifacts and those from Harappa. Vats also noted similarities in seals and writing found at both sites. Based on these reports, Marshall brought experts together to study the findings. By 1924, Marshall believed the discoveries were important and shared his thoughts in the Illustrated London News.
Later, British scholar Archibald Sayce pointed out that similar seals had been found in ancient Mesopotamia and Iran, helping date the artifacts. Systematic excavations at Mohenjo-daro began in 1924–25 with K. N. Dikshit, followed by H. Hargreaves (1925–1926) and Ernest J. H. Mackay (1927–1931). By 1931, much of Mohenjo-daro had been studied, though some work continued, including efforts led by Mortimer Wheeler, who became ASI director in 1944, and Ahmad Hasan Dani.
After India was divided in 1947, most Indus Valley sites were in Pakistan. The Archaeological Survey of India focused on the Ghaggar-Hakra river system in India, where some sites were found. Many of these sites were local cultures with connections to the Harappan civilization, but few were fully developed Harappan cities. By 1977, about 90% of Harappan script seals were found in Pakistan, while the rest were in India. By 2002, over 1,000 Harappan cities and settlements had been reported, with about 100 studied, mostly near the Indus and Ghaggar-Hakra rivers. Only five major cities—Harappa, Mohenjo-daro, Dholavira, Ganeriwala, and Rakhigarhi—were identified. By 2008, 616 sites were reported in India and 406 in Pakistan.
In India, the ASI focused on connecting archaeology to national identity after 1947. In Pakistan, efforts to preserve Islamic heritage meant early sites were studied by foreign archaeologists. After the partition, Mortimer Wheeler helped establish institutions in Pakistan and worked with UNESCO to protect Mohenjo-daro. Other international projects included the German Aachen Research Project, the Italian Mission to Mohenjo-daro, and the US Harappa Archaeological Research Project. In the 1970s, French archaeologist Jean-François Jarrige studied the site of Mehrgarh in Balochistan after a flood exposed it.
Chronology
The cities of the ancient Indus had social hierarchies, a writing system, large planned cities, and long-distance trade. These features help archaeologists recognize them as a fully developed civilization. The mature stage of the Harappan civilization lasted from about 2600 to 1900 BCE. When including earlier and later cultures—Early Harappan and Late Harappan—the entire Indus Valley Civilization may have existed from the 33rd to the 14th centuries BCE. This civilization is part of the Indus Valley Tradition, which also includes the pre-Harappan settlement of Mehrgarh, the earliest farming site in the Indus Valley.
Scholars use different ways to divide the history of the Indus Valley Civilization. One common method separates it into Early, Mature, and Late Harappan phases. Another approach, proposed by Shaffer, divides the broader Indus Valley Tradition into four eras: the pre-Harappan "Early Food Producing Era," and the Regionalisation, Integration, and Localisation eras. These roughly match the Early Harappan, Mature Harappan, and Late Harappan phases.
Pre-Harappan era: Mehrgarh
Mehrgarh is a Neolithic (7000 BCE to about 2500 BCE) mountain site in the Balochistan province of Pakistan. It provided new information about the beginning of the Indus Valley Civilization. Mehrgarh is one of the earliest places in South Asia with evidence of farming and animal raising. It showed similarities to the Near Eastern Neolithic, including domesticated wheat, early farming practices, pottery, other artifacts, and domesticated plants and animals.
Jean-Francois Jarrige believes Mehrgarh developed independently. He points out that some people assume farming was fully introduced from the Near East to South Asia. However, similarities between Neolithic sites in eastern Mesopotamia and the western Indus Valley suggest a continuous cultural connection between those areas. Jarrige argues that Mehrgarh has a unique local origin and is not simply a less important part of the Near Eastern Neolithic culture.
Lukacs and Hemphill suggest that Mehrgarh began with local development. They note that there is a strong connection between the Neolithic and Chalcolithic (Copper Age) cultures of Mehrgarh. However, dental evidence shows that the Chalcolithic population was not directly descended from the Neolithic population, indicating some level of genetic exchange. Mascarenhas et al. (2015) report that new body types, possibly from West Asia, appear in Mehrgarh graves during the Togau phase (3800 BCE).
Gallego Romero et al. (2011) explain that their research on lactose tolerance in India suggests that genetic contributions from West Eurasia, identified by Reich et al. (2009), mainly came from Iran and the Middle East. They also state that the earliest evidence of cattle herding in South Asia comes from the Indus River Valley site of Mehrgarh and dates to 7,000 years before present.
Early Harappan
The Early Harappan Ravi Phase, named after the nearby Ravi River, lasted from about 3300 BCE to 2800 BCE. It began when farmers from the mountains slowly moved between their mountain homes and the lowland river valleys. This phase is connected to the Hakra Phase, found in the Ghaggar-Hakra River Valley to the west, and came before the Kot Diji Phase (2800–2600 BCE, Harappan 2), named after a site in northern Sindh, Pakistan, near Mohenjo-daro. The earliest examples of the Indus script date to the 3rd millennium BCE.
The mature stage of earlier village cultures is shown by Rehman Dheri and Amri in Pakistan. Kot Diji represents the time leading up to the Mature Harappan period, with the citadel showing that leaders had control over the area and life became more urban. Another town from this stage was found at Kalibangan in India on the Hakra River.
Trade networks connected this culture to other nearby cultures and faraway places where they obtained materials like lapis lazuli and other items used for making beads. By this time, villagers had grown many crops, including peas, sesame seeds, dates, and cotton, as well as raised animals like water buffalo. Early Harappan communities moved to large cities by 2600 BCE, where the Mature Harappan phase began. Recent research shows that people from the Indus Valley moved from villages to cities.
The final stages of the Early Harappan period are marked by the building of large walled settlements, the growth of trade networks, and the merging of regional communities into a more similar material culture, including pottery styles, ornaments, and stamp seals with Indus script. This led to the transition into the Mature Harappan phase.
Mature Harappan
According to Giosan et al. (2012), the slow movement of monsoons across Asia allowed the Indus Valley villages to grow by managing the floods of the Indus River and its tributaries. Farming supported by floods led to large food supplies, which helped cities develop. The people of the Indus Valley did not use irrigation systems and relied mainly on monsoon rains that caused summer floods. Brooke noted that the growth of large cities happened at the same time as rainfall decreased, which may have caused people to move to bigger urban areas.
According to J.G. Shaffer and D.A. Lichtenstein, the Mature Harappan civilization was a mix of the Bagor, Hakra, and Kot Diji traditions in the Ghaggar-Hakra valley, which is near the borders of India and Pakistan.
Maisels (2003) explained that the Harappan civilization formed from a combination of Kot Diji and Amri-Nal cultures. He stated that Mohenjo-daro and the Hakra-Ghaggar area were important in creating the Early Harappan civilization. In these areas, Hakra-style items appeared before Kot Diji-related items.
By 2600 BCE, Early Harappan communities became large cities. These cities included Harappa, Ganeriwala, Mohenjo-daro in modern Pakistan, and Dholavira, Kalibangan, Rakhigarhi, Rupar, and Lothal in modern India. More than 1,000 settlements have been found, mostly near the Indus and Ghaggar-Hakra Rivers and their tributaries.
The Indus Valley Civilization had a highly developed urban culture, making it the first urban center in the region. The careful planning of cities shows that local governments existed and could organize large projects. These governments valued public health and hygiene or access to religious rituals.
In cities like Harappa, Mohenjo-daro, and Rakhigarhi, the urban plan included the first known city sanitation systems. Homes or groups of homes had access to wells for water. Waste from a room that may have been used for bathing was directed to covered drains along major streets. Houses opened only to inner courtyards and smaller lanes. Some village house designs today still resemble those of the Harappans.
Indus Valley cities had advanced drainage and sewer systems, which archaeologists describe as well-planned and more advanced than many other societies of the time. Their architecture included dockyards, granaries, warehouses, brick platforms, and large walls, which may have been used for flood protection and defense.
The purpose of the citadel in these cities is still debated. Unlike Mesopotamia and ancient Egypt, no large monuments, palaces, or temples were built. Some structures may have been granaries. One city had a large public bath called the "Great Bath," which may have been used for religious or social purposes. The walls of the citadel may have been for flood protection rather than defense.
Most city residents were likely traders or artisans who lived in neighborhoods with others who had similar jobs. Materials from faraway places were used to make seals, beads, and other items. Artifacts found include glazed faience beads and steatite seals with images of animals, people, and undeciphered writing. Some seals were used to mark trade goods.
Although some homes were larger, Indus Valley cities were notable for their relatively equal access to water and drainage. This suggests a society with limited wealth differences.
Archaeological records do not clearly explain who ruled the Harappan cities or how. However, evidence shows complex decisions and large-scale resource use. For example, cities were built in uniform grid patterns with two levels, showing planning by an authority. The consistency of weights and measures across the region also suggests a central authority.
Some major theories about governance include:
– A single state or federation ruled most or all of the Indus Valley, supported by standardized weights and measures.
– Each city was self-governing, like independent city-states.
Copper was common at Indus sites, as shown by archaeology. Brett Hoffman’s 2019 study of Harappan copper found that copper was alloyed with tin, arsenic, and lead. He analyzed artifacts from 3300 to 1700 BCE, showing how copper was used for tools and other items. Production increased during the Kot Diji Phase, but earlier groups already knew about copper.
Major copper sources included Rajasthan (Khetri mines) and areas as far as Oman and Bahrain. The Aravalli Range in northwestern India was important for copper. A touchstone with gold streaks found in Banawali was likely used to test gold purity, a technique still used in some parts of India.
Recent research suggests that access to copper and bronze was widespread in Indus society, contrary to older ideas of elite control.
The people of the Indus Valley Civilization developed precise systems for measuring length, mass, and time. They used uniform weights and measures, with the smallest division on an ivory scale from Lothal being about 1.704 mm, the smallest recorded in the Bronze Age. Harappan engineers used a decimal system for measurements, including mass, as shown by their hexahedron weights.
Chert weights followed a 5:2:1 ratio, with weights of 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20, 50, 100, 200, and 500 units, each weighing about 28 grams.
Late Harappan
Around 1900 BCE, signs of a slow decline began to appear, and by about 1700 BCE, most cities had been abandoned. Studies of human bones from the site of Harappa in the 2010s showed that the end of the Indus civilization was marked by more violence between people and an increase in diseases such as leprosy and tuberculosis.
Historian Upinder Singh said, "The late Harappan period shows a breakdown of city connections and the growth of more rural areas."
Between 1900 and 1700 BCE, many new regional cultures appeared within the area of the Indus civilization. The Cemetery H culture was found in Punjab, Haryana, and western Uttar Pradesh. The Jhukar culture was in Sindh, and the Rangpur culture, known for its Lustrous Red Ware pottery, was in Gujarat. Other sites from the late Harappan period include Pirak in Balochistan, Pakistan, and Daimabad in Maharashtra, India.
The largest late Harappan sites were Kudwala in Cholistan, Punjab; Bet Dwarka in Gujarat; and Daimabad in Maharashtra. These places were still considered urban, but they were smaller and fewer than the cities of the mature Harappan period. Bet Dwarka was protected by walls and kept trade links with the Persian Gulf, but long-distance trade generally declined. At the same time, farming became more varied, with different crops and the practice of growing two crops in the same area. People also moved their homes more toward the east and south.
The pottery of the late Harappan period showed some similarities to the mature Harappan style but had differences. Many sites remained occupied for centuries, but their cities became less developed. Items like stone weights and carved female figures became rare. Some circular seals with geometric designs were found, but they lacked the Indus script used in earlier times. Writing became very rare and was mostly found on broken pottery. Long-distance trade decreased, but local cultures created new types of glass, faience, and carved beads. City features like drains and public baths were no longer maintained, and new buildings were poorly made. Stone statues were destroyed, and valuables were hidden, suggesting unrest. Animal and human remains were sometimes left unburied in the streets or abandoned buildings.
By the later half of the 2nd millennium BCE, most late Harappan settlements were completely abandoned. Later material culture showed temporary camps, likely used by a nomadic and pastoralist population, with simple handmade pottery. However, in Punjab, Haryana, and western Uttar Pradesh, there was more continuity between late Harappan and later cultures, mostly in small rural villages.
In 1953, Sir Mortimer Wheeler suggested that the arrival of the Aryans from Central Asia caused the decline of the Indus civilization. He pointed to 37 skeletons found in Mohenjo-daro and references to battles in the Vedas. However, later scholars rejected this idea because the skeletons were from after the city was abandoned, and no skeletons were found near the citadel. Studies by Kenneth Kennedy in 1994 showed that marks on the skulls were caused by erosion, not violence.
In the Cemetery H culture (a late Harappan phase in Punjab), some designs on funerary urns were linked to Vedic literature, such as peacocks with hollow bodies and small human figures, possibly representing souls, and a hound, which may symbolize the hound of Yama, the god of death. This might suggest new religious beliefs, but there is no evidence that the Cemetery H people destroyed the Harappan cities.
Possible reasons for the decline of the Indus Valley Civilization (IVC) include changes in river courses and climate shifts that also affected nearby regions. By 2016, many scholars believed that drought and reduced trade with Egypt and Mesopotamia caused the collapse of the Indus civilization. A major drought and cooling event 4,200 years ago, which began the Meghalayan Age, may have contributed to this.
The Ghaggar-Hakra river system relied on monsoon rains. From about 1800 BCE, the climate became cooler and drier, linked to weaker monsoons. The monsoon rains decreased, causing less flooding and making farming less reliable. As the Ghaggar-Hakra river moved closer to the Himalayas, floods became less predictable, harming agriculture.
The lack of water led to the civilization’s decline and the movement of people eastward. According to Giosan et al. (2012), IVC residents did not use irrigation and relied on seasonal monsoons for farming. As monsoons shifted south, floods became too unpredictable for farming. People moved to the Ganges basin, where they lived in small villages and farms. These small communities did not produce enough surplus to support trade, leading to the end of cities.
Archaeological findings show that the decline of Harappa caused people to move east. Possehl noted that after 1900 BCE, the number of sites in modern India increased from 218 to 853. Andrew Lawler said, "Excavations along the Ganges plain show cities began to appear there around 1200 BCE, just a few centuries after Harappa was abandoned and much earlier than previously thought." Jim Shaffer described a continuous series of cultural changes, similar to those seen in other parts of the world, linking the two major urban periods in South Asia.
At sites like Bhagwanpura in Haryana, archaeologists found evidence of overlap between late Harappan pottery and early Painted Grey Ware pottery, associated with the Vedic culture (around 1200 BCE). This site shows different groups living in the same village but using different pottery and house types. Over time, late Harappan pottery was replaced by Painted Grey Ware pottery. Other changes included the introduction of horses, iron tools, and new religious practices.
At Rojdi in Saurashtra, excavations from 1982–83 showed cultural continuity between the Harappan civilization and later South Asian cultures. However, many aspects of the Harappan social and cultural systems were lost. The second major urban period in India, beginning with the Northern Black Polished Ware
Post-Harappan
Previously, experts thought that the decline of the Harappan civilization stopped urban life in the Indian subcontinent. However, the Indus Valley Civilization did not end suddenly, and many aspects of the Indus culture appeared in later societies. The Cemetery H culture may represent the Late Harappan period across areas like Punjab, Haryana, and western Uttar Pradesh, while the Ochre Coloured Pottery culture followed it. David Gordon White mentions three other scholars who have shown that parts of the Vedic religion may have come from the Indus Valley Civilization.
As of 2016, archaeological findings suggest that the Late Harappan material culture may have lasted until about 1000–900 BCE and existed at the same time as the Painted Grey Ware culture. Harvard archaeologist Richard Meadow notes that the Late Harappan settlement of Pirak was continuously inhabited from 1800 BCE until the arrival of Alexander the Great in 325 BCE.
After the Indus Civilization became more localized, regional cultures developed, showing some influence from the Indus Civilization. In the former city of Harappa, burial sites have been found that match a regional culture called the Cemetery H culture. At the same time, the Ochre Coloured Pottery culture spread from Rajasthan into the Gangetic Plain. The Cemetery H culture is the earliest known example of cremation, a practice common in Hinduism today.
People from the Indus Valley Civilization moved from the Indus and Ghaggar-Hakra river valleys toward the Himalayan foothills of the Ganga-Yamuna basin.
Genetics
In 2019, a study by Shinde et al. examined genetic information from a female skeleton discovered in a cemetery linked to the Indus Valley Civilization (IVC) in Rakhigarhi, Haryana, India. The skeleton is estimated to be about 2,800–2,300 BCE. The analysis showed that most of the genetic material was closely related to ancient Iranian hunter-gatherers from the Mesolithic period. A smaller part of the genome was connected to the Andamanese hunter-gatherers, which represents a type of early South Asian ancestry known as Ancient Ancestral South Indian (AASI). The genetic data did not include traits linked to Western Steppe Herders or Anatolian Neolithic farmers. The genetic makeup of this IVC individual is similar to the main genetic traits found in modern South Asians. Some evidence suggests the possibility of matrilocality, though this remains debated.