The Indus Civilization is among the world's earliest civilizations. It peaked around 2500 BCE in the western part of South Asia, declined during the mid-2nd millennium BCE and was forgotten until its rediscovery in the 1920s by R.D. Banerjee.
Geographically, it was spread over an area of some 1,260,000 sqkm, comprising the whole of modern day Pakistan and parts of modern-day India and Afghanistan. Thus there is an Indus Valley site on the Oxus river at Shortughai in northern Afghanistan (Kenoyer 1998:96) and the Indus Valley site Alamgirpur at the Hindon river is located only 28 km from Delhi. At its peak, the Indus Civilization may have had a population of well over five million.
The Indus civilization is still poorly understood. Its very existence was forgotten until the 20th century. Its writing system remains undeciphered. Among the Indus civilization's mysteries are fundamental questions, including its means of subsistence and the causes for its sudden disappearance beginning around 1900 BCE. We do not know what language the people spoke. We do not know what they called themselves. All of these facts stand in stark contrast to what is known about its contemporaries, Mesopotamia and ancient Egypt.
To date, over 1,052 cities and settlements have been found, mainly in the general region of the Hakra-Ghaggar river and its tributaries. Among the settlements were the major urban centers of Harappa and Mohenjo-daro, as well as Lothal, Dholavira, Ganweriwala, Kalibanga, and Rakhigarhi.
