An Integrated Polity
One of the features of the Indus civilization that most struck early researchers was its apparent uniformity: The material found in sites throughout the Indus realms seemed entirely uniform, with no regional or chronological variation. Closer familiarity with the Indus material and the establishment of a sequence of development at a few sites, such as Harappa, have dispelled this impression of complete invariability: Some changes through time have been established and some regional variations defined. Nevertheless, there remains a considerable degree of uniformity in the material found throughout the Indus realms, reflecting a culturally integrated polity with strongly developed internal distribution networks.
To a large extent, the people of the Indus realms would have been selfsufficient in food (although the larger towns and the cities would have needed to draw foodstuffs from their hinterland to support their large populations, which included large numbers of nonfarming citizens). Foodstuffs were nevertheless transported between different regions of the Indus realm: The vast majority have left no trace, but date stones at Mohenjo-daro and the bones of dried marine fish at Harappa provide tangible evidence that this occurred.
The raw materials of different regions were also transported to other parts of the Indus realms. Whereas in earlier times, local sources of flint were exploited by the inhabitants of each region, during the Harappan period the very high-quality brownish gray flint of the Rohri Hills was intensively extracted and distributed to every part of the Indus polity, either as a raw material or in the form of finished artifacts: For example, most of the stone tools at Balakot were acquired in finished form.
Shells, used particularly as the main material for making bangles, were gathered in large quantities on the Makran and Gujarat coasts. Some were processed locally and distributed either as blanks or as finished objects while others were transported intact to major settlements where they were cleaned and worked. Often individual workshops concentrated on producing a particular type of shell artifact or on working a particular variety of shell. Similarly, there were lapidary workshops both near the sources of agate, carnelian, and other gemstones and in major settlements far from these sources.