Definition
The Indus Valley civilization, also called the Harappan civilization, was one of the world's earliest complex societies. It flourished from roughly 2600 to 1900 BCE along the Indus River and its tributaries, in what is now Pakistan and northwest India.
It is named for two of its great cities, Harappa and Mohenjo-daro. These were not haphazard settlements but carefully planned cities, built on grids with standardized brick, advanced drainage, and public buildings — among the most sophisticated urban planning of the ancient world.
Why it matters
How it works
The Indus civilization depended on the river's floods and on a network of trade that reached as far as Mesopotamia. Its cities were strikingly uniform, which suggests strong shared standards, yet archaeologists have found no obvious palaces or grand royal tombs — so the nature of its government is still debated.
Around 1900 BCE the great cities were gradually abandoned. The causes are uncertain and probably combined climate change, shifting rivers, and disruption of trade. Because the script cannot be read, the Indus Valley remains one of the most intriguing puzzles in ancient history.