For more background information on religions see: http://home.comcast.net/~mruland/WHAP/Notes/foundations/wreligion.htm
The Aryan invasion of the subcontinent around 1,500 B.C.E. brought with it a new religion that featured a pantheon of gods that the Aryans worshiped through ritualism and with burnt sacrifices. Over the next thousand years, the religion matured, probably incorporating some elements of Harappan theology and certainly establishing a rigid social structure.
Around 500 B.C.E., Indians began to record their extensive oral religious traditions in what has become known as the Vedic literature. The oldest of the four Vedas is the Rig-Veda, and it is there that the Hindu creation myth and the basis for the caste system can be found. Another glimpse of the origins of the Hindu caste system can be seen in The Law of Manu, written around 200 C.E., viewed as a guide to proper behavior for Hindus. Selections from both texts are included below.
The Rig Veda is a collection of hymns counted among the four Hindu religious scriptures known as the Vedas, and contains the oldest texts preserved in any Indo-Iranian language & the world. It was first orally passed down in India & then later on finally was documented. It consists of 1,017 hymns (1,028 including the apocryphal valakhilya hymns 8.49-8.59) composed in Vedic Sanskrit, many of which are intended for various sacrifical rituals. These are contained in 10 books, known as Mandalas. This long collection of short hymns is mostly devoted to the praise of the gods. However, it also contains fragmentary references to historical events, notably the struggle between the early Vedic people (known as Vedic Aryans, a subgroup of the Indo-Aryans) and their enemies, the Dasa.
The chief gods of the Rig-Veda are Agni, the sacrificial fire, Indra, a heroic god that is praised for having slain his enemy Vrtra, and Soma, the sacred potion, or the plant it is made from. Other