The Bronze Age Begins to Collapse

1900 BCE

Tectonic movements shift the silt in areas around Mohenjo-daro (in present-day Sindh, Pakistan), and this is accompanied by the rise of the Arabian Sea along the coast of the lower Indus Valley. These result in repeated floodings of the Indus River, a rise in soil salinity, and a consequently poor agricultural output. Scholars speculate that changes in the direction of flow of rivers such as the Sutlej, coupled with the seasonal drying up of the Ghaggar-Hakra River and a cooling of the atmosphere, cause a significant decline in the monsoon in this time frame. This parallels a series of crises in the periphery of the Mediterranean Sea, which leads to the destruction of cities throughout Anatolia and the Levant. The polities of Egypt and Mesopotamia face extreme political pressure and a decline in global trade causes a scarcity of craft materials as well as reduced diplomatic exchanges. The combination of all these contributes to a gradual de-urbanisation of Harappan sites. South Asian population centres move eastward, and regional cultures grow.