You are probably familiar with the term caste, which refers to a set of hierarchically ordered social categories. The ideal order was laid down in the Dharmasutras and Dharmashastras. Brahmanas claimed that this order, in which they were ranked first, was divinely ordained, while placing groups classified as Shudras and 'untouchables' at the very bottom of the social order. Positions within the order were supposedly determined by birth.

The Dharmasutras and Dharmashastras also contained rules about the ideal 'occupations' of the four categories or varnas. Brahmanas were supposed to study and teach the Vedas, perform sacrifices and get sacrifices performed, and give and receive gifts. Kshatriyas were to engage in warfare, protect people and administer justice, study the Vedas, get sacrifices performed, and make gifts. The last three occupations were also assigned to the Vaishyas, who were in addition expected to engage in agriculture, pastoralism and trade. Shudras were assigned only one occupation – that of serving the three 'higher' varnas.

According to the Shastras, only Kshatriyas could be kings. However, several important ruling lineages probably had different origins. The social background of the Mauryas, who ruled over a large empire, has been hotly debated. While later Buddhist texts suggested they were Kshatriyas, Brahmanical texts described them as being of 'low' origin. The Shungas and Kanvas, the immediate successors of the Mauryas, were Brahmanas. In fact, political power was effectively open to anyone who could muster support and resources, and rarely depended on birth as a Kshatriya.

These complexities are reflected in another term used in texts to refer to social categories – jati. In Brahmanical theory, jati, like varna, was based on birth. However, while the number of varnas was fixed at four, there was no restriction on the number of jatis. In fact, whenever Brahmanical authorities encountered new groups – for instance, people living in forests such as the nishadas – or wanted to assign a name to occupational categories such as the goldsmith or suvarnakara, which did not easily fit into the fourfold varna system, they classified them as a jati. Jatis which shared a common occupation or profession were sometimes organised into shrenis or guilds.

Given the diversity of the subcontinent, there were, and always have been, populations whose social practices were not influenced by Brahmanical ideas. When they figure in Sanskrit texts, they are often described as odd, uncivilised, or even animal-like. In some instances, these included forest-dwellers – for whom hunting and gathering remained an important means of subsistence. Categories such as the nishada, to which Ekalavya is supposed to have belonged, are examples of this.

While the Brahmanas considered some people as being outside the system, they also developed a sharper social divide by classifying certain social categories as 'untouchable'. This rested on a notion that certain activities, especially those connected with the performance of rituals, were sacred and by extension 'pure'. Those who considered themselves pure avoided taking food from those they designated as 'untouchable'. The Manusmriti laid down the 'duties' of the chandalas... They had to live outside the village, use discarded utensils...