The recovery of India's immense history owes much to Western and particularly British researches; yet attempts to compress it often concentrate on the brief Imperial period. This up-to-date survey treats the latter as merely the penuitimate chapter in a story that begins in the 3rd millennium BC with the Indus Valley civilization. The influx of pastoral nomads - first in a long series of invasions from the north established the Vedic religion, whose assimilation of popular cults and formalization in Sanskrit writing and social castes supplied the cohesion which subsequent events - the Moghul incursions, the British Empire, the rise of modern India - did little to change. The enduring distinctiveness of India, its often bewildering diversity of unity, emerges as a product of geographical simplicity and great historical complexity.