For all its achievements, the Indus civilization is still poorly understood.Its very existence was forgotten until the twentieth century.Among the settlements were the major urban centers of Harappa and Mohenjo-daro, as well as Dholavira, Ganweriwala, Lothal, and Rakhigarhi.At its peak, the Indus civilization may have had a population of well over five million.
Geographically, it was spread over an area of some 1,250,000 km², comprising the whole of modern-day Pakistan and parts of modern-day India and Afghanistan.This is hotly disputed by contemporary Indian historians and linguists, who argue that the idea that foreigners always dominated India was conducive to European imperial ambitions.Among the Indus civilization's mysteries, however, are fundamental questions, including its means of subsistence and the causes for its sudden disappearance beginning around 1900 Lack of information until recently led many scholars to negatively contrast the Indus Valley legacy with what is known about its contemporaries, Mesopotamia and ancient Egypt, implying that these have contributed more to human development.(It is called pre-Harappan because remains of this widespread culture are found in the early strata of Indus civilization cities.) Trade networks linked this culture with related regional cultures and distant sources of raw materials, including lapis lazuli and other materials for bead-making. Subsequently, a unified culture emerged throughout the area, bringing into conformity settlements that were separated by as much as 1,000 km and muting regional differences.Villagers had, by this time, domesticated numerous crops, including peas, sesame seeds, dates, and cotton, as well as a wide range of domestic animals, including the water buffalo, an animal that remains essential to intensive agricultural production throughout Asia today. So sudden was this culture's emergence that early scholars thought that it must have resulted from external conquest or human migration.