During medieval period, society in large parts of the Indian subcontinent was already divided according to the rules of varna. These rules, as prescribed by the Brahmanas, were accepted by the rulers of large kingdoms. The difference between the high and low, and between the rich and poor, increased. Under the Delhi Sultans and the Mughals, this hierarchy between social classes grew further. There were, however, other kinds of societies as well. Many tribal societies in the subcontinent did not follow the social rules and rituals prescribed by the Brahmanas. Nor were they divided into numerous unequal classes.