What is the current state of knowledge about Indus Valley Civilization?
The Indus Valley empire stretched from Afghanistan to Bangladesh, in a band across northern south Asia. Despite the failed arguments of nay-sayers Witzel and Farmer, the IVC was a literate culture whose Indus script later developed into Brahmi script, the source of all non-Arabic south Asian writing systems.
The earliest IVC sites are in Haryana, North India (7380 BC) and Merhgarh, Pakistan (8th millennium BC). The culture declined around 2000 BC, probably as a result of drought and famine caused by changes in monsoonal rain. The largest IVC sites are in north India and include Rakhigarhi.
The Indus Valley empire traded with Sumer and Egypt, and may have been mentioned as Meluhha in Sumerian clay tablets describing ships at Sumerian docks. However, the Sanskrit word mleccha actually means non-Hindu barbarian. There are mentions of a place called 'Aratta' in Sumerian texts, described as full of artisans and fabulous wealth, and the homeland of the goddess Inanna. (Arata is a Sanskrit name for the Punjab, in northwest India/Pakistan.)
There have long been furious on-going arguments as to whether the IVC was Indo-Aryan, Dravidian or something else. There is good linguistic evidence for an Indo-Aryan Indus Valley culture, based on comparison of the Indus script signs with Brahmi script and the few known signs of Linear Elamite. However, some theorists still insist that the speakers of Sanskrit and Prakrit were not indigenous to India and did not live there during the IVC. The whole controversy reminds me of the archeological and linguistic authorities of the period telling Michael Ventris that Linear B could not possibly encode Greek, because the Linear B tablets were 'too old.' (As it turned out, Ventris was right, and he managed to decipher Linear B by identifying repeated strings of Linear B signs as the names of certain towns on Crete.)
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