"In the days when historian supposed that history had begun with Greece, Europe gladly believed that India has been a hotbed of barbarism. In 1924 the world of scholarship was again roused by news from India. Sir John Marshall announced that he had discovered at Mohenjo-daro, on the western bank of the lower Indus, remains of what seemed to be an older civilization than any yet know to historians.
The indications are that Mohenjo-daro was at its height when Cheops built the first great pyramid; that it had commercial, religious, and artistic connections with Sumeria, and Babylonia. It survived over 3000 years, until the third century before Christ."
(source: "The Story of Civilization: Our Oriental Heritage - By Will Durant ISBN 1567310125 p 394-396).