The Indus Valley Civilization was the first major urban culture of South Asia. The peak was between 2600 and 1900 BC roughly.The samples are huge - about 1000 settlements spreading all of modern Pakistan, and parts of India and Afghanistan.The main corpus of writing include 2,000 inscribed brief seals and tablets of 6 to 26 symbols each which are still undeciphered.There are several competing theories about the language (unrelated/Aryan/Mundari/Dravidian) which the Indus script represents.
But it appears that there was an equally strong multi-racial and multi-lingual existence then which has further contributed to the difficulties in decipherment.
