The Indus cities are abandoned

From around 1900 BCE the great Indus cities are progressively abandoned, the script falls out of use, the weight standard disappears and the population disperses into smaller village settlements to the east. There is no destruction layer and no evidence of invasion — the old Aryan invasion explanation has been abandoned. Weakening monsoons and the drying of the Ghaggar-Hakra river system are the leading causes, plausibly connected to the same climatic deterioration seen further west.