Decline of Indus Valley Civilisation (IVC) | History for UPSC CSE PDF Download

Decline of Indus Valley Civilisation

• There is evidence that by around 1800 BCE, most Mature Harappan sites in places like Cholistan had been abandoned.
• Concurrently, there was a population increase into new settlements in Gujarat, Haryana, and western Uttar Pradesh.
• Many scholars believe that climatic change was to blame for the fall of the Indus Valley Civilization.
• Some scholars believe that the drying of the Saraswati River, which began approximately 1900 BCE, was the primary cause of climatic change, while others believe that a large flood hit the area.
• Various components of the Indus Civilisation have been discovered in succeeding cultures, indicating that the civilization did not vanish suddenly owing to an invasion.
• Many researchers believe that changes in river patterns caused the big civilisation to disintegrate into smaller settlements known as late Harappan civilizations.

Decline of IVC - Causes

The decline of the Indus Valley Civilization (IVC) is attributed to several factors:

• One reason is the decreasing fertility of the soil, caused by the rising salinity due to desert expansion.
• Another cause may be a sudden subsidence or uplift of the land, resulting in floods.
• While the ancient cultures of Mesopotamia persisted after 1750 BCE, the Harappan culture began to vanish around the same period.
• There are signs of cultural changes, indicated by the slow influx of new peoples into the Indus basin during the later stages of Harappan culture.
• Evidence of insecurity and violence appears in the last phase of Mohenjo-Daro, such as:
  • Buried jewellery
  • Huddled skulls
• New pottery styles were found at some Harappan sites in Baluchistan, including Painted Grey Ware, which was typically linked to the Vedic people.
• This influx of new people is thought to be linked to barbarian horse-riding groups from Iran.
• However, these newcomers did not arrive in sufficient numbers to completely overrun the Harappan cities in Punjab and Sindh.
• Although the Rig Vedic Aryans predominantly settled in the region of the Seven Rivers, where the Harappan culture thrived, there is no evidence of large-scale conflict between them.
• The Harappan culture persisted, albeit weakened, in the peripheral areas such as Gujarat, Rajasthan, and western Uttar Pradesh.
• By around 1700 BCE, most towns of the IVC had been abandoned.

Theories of Decline

• Some believe the decline of the Harappan civilisation was due to reduced fertility from increasing soil salinity, which resulted from the expanding desert nearby. 
•  Others suggest that the Harappan culture was wiped out by the Aryans. 
•  During the later stages of the Harappan culture, unusual tools and pottery suggest the gradual arrival of new groups in the Indus basin. 
•  In the final phase of Mohenjo-daro, there are signs of insecurity and violence, with jewellery buried in various locations and skulls found together in one spot. 
•  New pottery styles have also been discovered at some Harappan sites in Baluchistan. 
•  In several sites in Punjab and Haryana, Painted Grey Ware, typically linked to Vedic people, has been found alongside some later Harappan pottery. 
•  Although the Rig Vedic Aryans mainly settled in the land of the Seven Rivers, where the Harappan culture once thrived, there is no evidence of large-scale conflict between the Harappans and the Aryans. 

Aryan Invasion

Aryan's Route 

• Ramaprasad Chanda originally suggested that the Harappan civilisation was destroyed by Aryan invaders, but he later changed his view. Mortimer Wheeler expanded on this idea.
• While the Rig Vedic Aryans mainly settled in the Seven Rivers area, there is no proof of large-scale conflict between the Harappans and the Aryans.
• Some signs of trouble and violence can be seen in the last phase of Mohenjo-daro, which hint at a complicated interaction rather than simple destruction.
• Wheeler referred to mentions in the Rig Veda of various types of forts and attacks on walled towns as signs of conflict, but these references should not be taken as clear proof of an invasion.

Factors in the Decline of Harappan Civilisation

The decline of the Harappan civilisation has been linked to several reasons, including:

• Reduced soil fertility due to increased salinity from the expanding desert.
• Sudden land subsidence or uplift leading to floods.
• Gradual influence from new groups, shown by exotic tools and pottery appearing in later Harappan phases.

New pottery and tools, possibly reflecting foreign influence, have been found in sites such as Baluchistan and Punjab. These discoveries suggest a slow influx of new peoples into the Indus basin, but they did not overpower the existing Harappan culture.

Overall, while the presence of the Aryans in the region is noted, the evidence does not support the idea of total destruction of the Harappan civilisation by an invading force.

Natural Disasters

Environmental and Geographical Factors

1. Floods and Silt Layers:

   • Layers of silt found at Mohenjodaro, Chanhudaro, and Lothal suggest destruction caused by rising rivers.
   • Multiple layers of silt at Mohenjodaro indicate repeated flooding, which contributed to the downfall of the Harappan civilisation.
   • Flooding events divided the city's history into distinct periods of occupation.
   • Evidence includes silty clay and crumbled debris covering homes and streets, indicating rebuilding over earlier structures.

2. Tectonic Activity:

   • The Indus region was prone to earthquakes.
   • Tectonic shifts might have created a natural barrier, forming a large lake around Mohenjodaro.

3. Soil and Agriculture:

   • Decline may also be attributed to reduced soil fertility caused by salinity from the advancing desert.
   • The Indus River carried more alluvial soil than the Nile, enriching the flood plains.
   • Harappans planted crops (wheat and barley) in November, after floodwaters receded, and harvested them by April before the next flood.
   • Evidence of ploughed fields from Kalibangan in Rajasthan shows agricultural activity, despite the absence of hoes or ploughshares.

Cultural and Social Aspects

1. Invasions and New Peoples:

   • Some theories suggest that the Harappan culture was overrun by Aryans.
   • Later Harappan phases show exotic tools and pottery, indicating the arrival of new peoples in the Indus basin.
   • New types of weapons (axes, daggers, and knives) in the upper layers of Mohenjodaro suggest foreign influence.

2. Conflict and Insecurity:

   • Signs of conflict in Mohenjodaro’s final phase include hidden treasures and grouped skulls, implying insecurity and possible violence.

3. Burial Practices:

   • A cemetery from the late Harappan phase reveals new pottery styles, further suggesting the presence of different peoples.

Urban Planning and Infrastructure

1. Flood Protection: Burnt brick walls were built for protection, suggesting annual floods were common.
2. Drainage System: Mohenjodaro had an impressive drainage system, reflecting advanced urban planning and water management.

Ecological Imbalance

Scholars have proposed various reasons for the decline of the Harappan civilisation, focusing on environmental and social problems. Some suggest that the soil became less fertile due to increased salinity from the expanding desert.

• Others believe that sudden changes in the land's elevation caused flooding, while some argue that the Harappan culture was overrun by the Aryans.
• In the later stages of Harappan culture, the presence of unfamiliar tools and pottery suggests that new groups were slowly entering the Indus basin.
• There are indications of insecurity and violence in the final phase of Mohenjo-Daro, including buried jewellery and clustered skulls found at one site.
• While these artefacts largely seem Indian, they may also show some foreign influence.
• A cemetery from the late phase of Harappa reveals new pottery styles and similar pottery has been discovered at various Harappan locations in Baluchistan.
• In parts of Punjab and Haryana, Painted Grey Ware, linked to the Vedic people, has been found alongside late Harappan pottery.
• This influx can be linked to horse-riding groups from Iran, though they did not arrive in numbers sufficient to completely dominate the Harappan cities in Punjab and Sindh.
• Despite the Rig Vedic Aryans settling mainly in the area once occupied by Harappan culture, there is no evidence of large-scale conflicts between them.
• While the major cities of Harappa and Mohenjo-daro vanished, Harappan culture persisted in a diminished form in regions like Gujarat, Rajasthan, and western Uttar Pradesh.
• The origins of the Harappan culture remain as elusive as its decline.

Shifting Away of Indus

• According to Lambrick, changes in the path of the Indus River may have led to the decline of the Indus Valley civilization.
• The Indus transported significantly more alluvial soil than the Nile in Egypt, depositing it on the floodplains.
• Similar to how the Nile shaped Egypt and supported its inhabitants, the Indus formed Sindh and the key cities of the Harappan culture.
• Some believe that the civilization's decline was due to decreasing fertility from increasing salinity of the soil caused by the spread of a nearby desert.
• Others suggest a sudden subsidence or uplift of land that resulted in floods.
• Some argue that the Harappan culture was ultimately destroyed by the Aryans.
• In the later stages of the Harappan culture, unique tools and pottery suggest a gradual arrival of new groups in the Indus basin.
• Signs of insecurity and violence emerged in the final phase of Mohenjo-daro, including buried jewellery and clustered skulls.
• Walls made from burnt bricks indicate that floods occurred annually.
• The drainage system in Mohenjo-daro was quite impressive.
• It is likely that the Harappans used a wooden ploughshare, but it is unclear whether it was pulled by people or oxen.

Climatic Change

Climatic Change 

• While Mohenjodaro may have deteriorated due to natural floods, Harappan sites in the Ghaggar-Hakra valley faced ongoing drying out.
• The decline of the Harappan civilization is linked to several theories:
  • Some believe it was due to reduced soil fertility from increasing salinity caused by the desert's growth.
  • Others suggest sudden land changes led to flooding.
  • Some argue that the Aryans destroyed the Harappan culture.
• A crucial factor for the area's fertility appears to be the annual flooding of the Indus River.
• In later phases of the Harappan culture, some unusual tools and pottery suggest the gradual arrival of new groups in the Indus basin.
• Signs of unrest and violence emerged in the last phase of Mohenjo-daro, including buried jewellery and clustered skulls.
• The Harappan culture at other sites slowly declined but continued in a weakened form in regions like Gujarat, Rajasthan, and western Uttar Pradesh.
• Perhaps no other civilization focused as much on health and cleanliness as the Harappans, as shown by their advanced drainage system.

Decline of Trade

• The decline in the lapis lazuli trade with Mesopotamia, as noted by Shereen Ratnagar, contributed to the downfall of the Harappan civilisation. Interaction with Mesopotamian cities may have helped Harappan culture to develop.
• The Harappans traded with regions including Rajasthan, Afghanistan, and Iran, and their cities also had commercial ties with those in the Tigris and Euphrates areas.
• Numerous Harappan seals have been found in Mesopotamia, suggesting that the Harappans copied some cosmetics from the urban population there.
• Mesopotamian records from around 2350 B.C. mention trade relations with Meluha, which is the ancient name for the Indus region.
• The structure of Harappa spans 5 km, making it the largest of its kind in the Bronze Age. No other urban complex of Harappan size has been discovered to date.

Conclusion

Many factors behind the decline of the Harappan civilisation are still unclear. The two key cities of Harappan culture, Harappa and Mohenjo-daro, vanished, but Harappan culture lingered in a diluted form in the outskirts of Gujarat, Rajasthan, and western Uttar Pradesh. Understanding the beginnings of the Harappan culture is as complex as deciphering its end. Several pre-Harappan settlements have been located in Baluchistan and Kalibangan in Rajasthan, but their relationship to the mature Harappan culture is not well understood. Interaction with Mesopotamian cities may have played a role in the evolution of the Harappan culture, reflecting the intricate nature of trade and cultural exchange during this era.