The work provides a critique of the current theories of the caste system which locate its essence in endogamy and argues that present morphology of caste is the result of the changes the institution has undergone over centuries of its existence, but the origins are embedded in the ecology of the Vedic cattle-keepers. Processes of patriarchy and state formation have played a crucial role in its evolution and its ideology has made significant conceptual adjustments in the course of its long history without however, abandoning its basic principles.