We have a number of clues to the organization of the Indus state. It seems that, unlike most early states, warfare played no part in the rulers' control. Most major settlements were fortified - but the enemy was river floodwaters, except in peripheral sites like Sutkagen Dor where envious neighbours or pirates were a threat.
The Indus civilization seems to have been a federated state. Each region had a major city: Mohenjo Daro and Harappa are best known, but Ganweriwala, Dholavira and Rakhighari are of similar size.
There are some major regional differences, for instance in economic activities, the treatment of the dead or religious structures (like Mohenjo Daro's Great Bath and Kalibangan's fire altars). Nevertheless, the overriding impression is of cultural uniformity.
All settlements, except small villages, had a citadel, with administrative and religious buildings, and a residential lower town with small workshops and larger industrial enterprises producing goods which were distributed throughout the civilization.
This meant that households right from Harappa in the north to Lothal in the south had stone tools made of finest quality Rohri Hills flint, bangles of Indian Ocean shell, metal tools of Aravalli Hills copper and so on.
There are variations in the size and complexity of houses, but all suggest a high standard of living. Farmers and fishers, herders and hunters were probably least prosperous - perhaps we can add others like miners, shell divers and those engaged in unpleasant industrial or civic tasks like cleaning out drains.
Craftspeople and merchants were probably better off, and at the apex of society there must have been rulers. It is tempting to see here the beginnings of the caste system, with its network of interrelationships, rights and obligations between different occupational specialists, and its high status religious specialists, the Brahmins.
The association of ritual structures, administrative buildings (such as warehouses and granaries) and elite housing in the citadels may well support the idea that the rulers of the Indus civilization were also its religious leaders.
