Decline of the Indus cities
Harappa and Mohenjo-daro empty as people move east

Around 1900 BC the great cities of the Indus valley began to empty, and their script and standard weights fell out of use. Weakening monsoons and drying rivers are the likely causes; people dispersed into villages further east, towards the Ganges plain and Gujarat.
Wikipedia (Russian) · Wikipedia (English) · 19th century BC
Meanwhile around the world (±25 years)
Europe
- c. 1900 BC Palace of Knossos — same year