The history of India is generally-regarded as the history of Aryans in India. It is widely believed that the Aryans originally belonged to Central Asia from where they migrated to India around 2500 B.C. They crossed the north-west passes and settled in the areas around the river Indus and its tributaries, driving the Dravidians inland.
They had, however, not advanced to the Gangetic Valley. This age is known as the Early Vedic Age. Later, the Aryans slowly occupied the whole of north India, driving the Dravidians to south India. This period is known as the Later Vedic Age.
An important aspect of the Aryan society is that they were divided into four classes: Brahmans, Kshatriyas, Vaishyas and Sudras; but, there was no rigid caste system. The Rigvedic Aryans were primarily agriculturists, though they also carried on trade and commerce.
They worshipped natural forces and Varuna and Indra were their chief deities. However, idol worship was not known to them. Sacrifices and daily prayers were important features of their religion.