The invasion of the Aryans formed the basis of the caste system that developed in India. The Aryans stressed the superiority of the lighter-skinned invaders over the darker-skinned indigenous peoples of India.
Indian society was divided into five castes:
Brahmins: the priestly caste. After their religious role decreased they became the caste of officialdom.
Kshatriya: warrior caste. The kshatriya class were direct descendants of the warriors that had conquered India.
Vaisya: the commoner caste. Generally the third caste comprised the merchants.
Sudras: represented the great bulk of the Indian population. Most of the sudras were peasants, artisans or others who worked in manual labor.
Untouchables: descendants of slaves or prisoners. The untouchables were given menial degrading work that no others would do.
The caste divisions in India were nearly absolute. People lived and died as members of a particular caste. Except in rare cases, marriages always took place within the caste.