There is first the scriptural evidence the most ancient Indian text, the Rig Veda, describes the great Sarasvati and its environs with precision. Subsequent Vedic literature &mdash the Mahabharata, the Brahmanas and Puranas &mdash corroborates this description, and goes on to mention the river&rsquos break-up and recession. Then comes the evidence from 19th-century British geographers who correlate the Sanskrit texts with their empirical findings. In the next century comes the archaeological evidence excavations show a large number of settlements along the river's course, dating back to the Indus Valley civilisation. Of these, Kalibangan is the best known today. Changes in the distribution pattern of these sites suggest that the Sarasvati started shrinking 5,000 years ago and, by 1900 BCE, much of its central basin was dry. But if the Sarasvati died during the Indus Valley period, how could she be described and praised in the Vedas which, according to Max Müller, were composed by &lsquoAryans&rsquo who settled in the region after 1400 BCE &mdash four centuries after it had dried up Why would the Rig Veda call a long-dead stream &ldquomighty&rdquo, &ldquoimpetuous&rdquo and &ldquobest of rivers&rdquo To find out, read The Lost River.