Religion has been a major preoccupation of the peoples of South India. Since from early times different strands of racial types and cultural layers formed one above the other chronologically it was but natural that different religious expressions should have characterised different periods in their history.
Apart from these since regionally also there were different cultures compartmentalized in rural areas and urban areas in the hinter lands and the coast land, the hilly regions and the plains, the forests and the cultivated lands and so forth but also the regions conventionalized by early Tamil experiences into Kurinji (the hill country), Mullai (the forest lands), Marudam (the cultivated lands), Neydal (the littoral) and Palai (a perversion of any of the above, namely a desert).
These tracts had such clear cut socio-cultural traits that they had their own Gods to worship and forms of worship. The Kurinji folk as evidenced by the Tolkappiyam worshipped Murugan. The Mullai or the pastoral people worshipped Mayon, the Tamil version of Krishna. The Marudam peasants naturally worshipped Indra, an Aryan celestial, known to the Tamils as Vendan, the king.
The Neidal or the fisher folk worshipped Varuna, the God of the seas1 as well as the shark which they propitiated naturally. This reference is not merely to a literary convention but a living socio-religious practice compelled by the local regional environment suitably embellished with the divine activities of these Gods and gave meaning to the beliefs of the mortals who worshipped them.
Apart from these, we know that totemic worship also was well known and widely practised. Rivers, mountains, animals, reptiles, birds etc. were objects of worship and deemed sources of protection. It was a tribal practice to hold such objects in reverence and this kind of religion also developed its own mythology.
In the case of the other areas of South India there is little evidence, literary or otherwise, of the nature of primitive worship. Still certain things were common to the entire area as perhaps to the whole world. Kaman, the God of love, Yama, the God of death, and such others were part of the mythology of the totem worshippers as well as the later groups.
As the Vedic Aryans spread over the whole of the peninsula in a series of peaceful migrations which covered a period of time the Aryan religion of the worship of the powers of nature influenced the local pre-Aryan religions and mythologies and were in their turn influenced thereby. This was a vast process of give and take, reconciliation and compromise – a large scale cultural bargain as it was. It is this cultural process that has been rather vaguely called Aryanisation.