Before the arrival of the Aryans sometime in 1500 B.C.E., India consisted of agricultural communities that lacked true social class. Around the 3rd millennium B.C.E , the Harappan civilization rose up around what today is Pakistan and northwest India, perhaps indicating the manifestation of the ruling elite; however, even then social class was not attached to individuals, but functioned under the jati system. Ancient Indians gathered up in towns and villages that eventually became kingships, each ruled by its own council of members – an elite group composed of hereditary bloodlines based on power and wealth. Each kingship or jati was composed of hundreds or thousands of nuclear families that performed similar functions for society; off course occupations varied within a single jati in order to sustain its population, but in general, each jati had a specific economic role within its system, perhaps under the control of larger kingships, like the cities of Mohenjo-Daro and Harappa. Each jati belonged to a form of unwritten social class dictated by their function in society; this meant that if a whole community changed its occupation to one that ranked higher (or lower) in the social scale, then the whole jati transitioned social levels.