The Indus civilization was one of the modern civilizations of its time. It lasted from 3300 BCE to 1300 BCE. However, its decline began around 1900 BCE and ended up around 1300 BCE. The reason for the decline of the Indus civilization is not very clear. Historians have different opinions on how such a big civilization ended up. However, most historians consider natural disasters as the main reason for the fall of this civilization.
- According to historians Mortimer Wheeler and Gordon Childe: The Aryan invasion was one of the reasons for the fall of this civilization.
- According to Wells, Madho Sarup Vats: The change in the course of the river.
- According to Aurel Stein: Drought affected the whole agricultural system in this region.
- According to Mackay, S. R. Rao, Raikes: Repeted Floods forced the people to shift to another region.
- According to D. P. Agrawal and Sood: Natural disasters such as the drying up of the Ghaggar River accelerated the fall of this civilization.
- Robert L. Raikes and George F. Dales: Blame the continuous earthquakes for the fall of this civilization.
Natural Causes
Earthquakes: The Indus Valley is located on the northwestern part of the Indian tectonic plate. And this region is a disturbing earthquake-prone area. Therefore, it is assumed that repeated earthquakes destroyed the Indus Valley Civilization. Nine layers of the Indus Valley Civilization have been discovered through excavations. These layers indicate that the Harappan people rebuilt cities and towns in this area.
Floods: Due to the development of an advanced drainage system, water accumulated in the Indus and other rivers, resulting in regular floods or tidal surges, which was also one of the important reasons for the decline of this civilization. It was found that many houses and streets were covered by alluvium. However, no clear evidence has been found so far in this regard.
Info: It is also assumed that the repeated earthquakes led to major flooding in this region.
Changes in weather and river course: Changes in the natural weather and the course of the Indus River resulting the decline of the Indus Valley Civilization. Historians such as Wells, M. Sarup Vats believe that the course of the Indus River was shifted from Mohenjodaro. This badly affected agriculture which was the main occupation of the people. This also created a scarcity of water. So people shifted from this region to the foothills of the Himalayas.
Info: However, this reason is not for the collapse of the whole Indus civilization but it only affected the Mohenjodaro.
Desert expansion: According to many historians, due to prolonged drought, salinity in the soil increased. As a result the Indus region gradually became a desert due to loss of fertility.
Disease: According to the research of Dr. G. R. Schug, vital diseases such as plague and leprosy rapidly increased here. Evidence of skeleton of bone leprosy has been found in Mohenjador. As a result, people might have migrated to a safer region.
Info: All of the above factors might have led to the failure of trade and commerce between Indus and Mesopotamia, Babylon and other central Asian regions. As a result, people migrated to the Himalayas, South or Eastern region.
Attacks by external enemies
A type of axe mark on a seal found in the Indus Valley and unburied skeletons on the street and throughout Mohenjodar. This indicates that the invaders came to India from Iran in the northwest. These invaders were Aryan. The Rigveda mentions the war of the Aryans with the non-Aryans of Harappa in the ‘Hariyupiya’.
Info: According to Mortimer Wheeler and Gordon Childe, the Aryans genocided the Indus people to capture this fertile and modern area and also it was the gateway to the rest of India.
Political instability
Political instability in municipal control was one of the reasons for the decline of this civilization. Later, the inefficient management of the ruling class of the Indus civilization, the weakness of the municipal system, social disunity and the lack of loyalty of the ruling class weakened the foundation of this civilization, which indirectly made the invasion of external enemies more effective.
Info: In addition, the conservative society of the Indus civilization did not accept the modernity of other civilizations (for example, the residents of Indus did not adopt the advanced irrigation system of Babylon).