The history of the Sāsānian period is often presented with Islamic bias, for the purpose of leading to conclusions which authors of the Islamic period wished to demonstrate, reflecting the conflicts and problems of their times. In Central Asia and in Afghanistan of today there persisted elements, probably rather heterogeneous, of the confederation known as the Hephthalites, which had an Indo-European core but had been infiltrated by various Turkish elements. Certain Iranian authors of the Islamic era have produced a summary classification of social divisions, based on a particular aspect of actual social conditions quite independent of the Muslim theoretical system. The seat of local government was generally in the citadel, but the central monument of the city, in proportion to its degree of conversion to Islam, was the Great Mosque. In pre-Islamic times Iranian society had been possessed of reserves of slaves and had retained them under Islam.

Iran shares with so many others a rapid sequence of social changes and hence has to cope with the passing of traditional society, and the creation of a new society. In view of the ecological conditions existing in much of the country, the nomadic-pastoral way of life is an admirable human response over extensive areas, and that there can be in these parts no other equally satisfactory economic activity, and associated tribal social organization. With the introduction of a costly irrigation scheme, pastoralism must give way to a regular and continuous form of land utilization such as agriculture or intensive animal husbandry. A significant element of the social scene in Iran today is the urban group. New urban dwellers just arrived from the countryside provide many heterogeneous elements for urban society, and it is often reported that a certain uneasiness, symptomatic of difficulties of adjustment, exists among the newcomers.

Iranian society occupies a unique situation within the Middle East. The country fulfils the criteria of a recognizable human unit with a culture that has been distinctive for many centuries. Iran has a pronounced physiography. Human settlement in Iran is concentrated on the interior piedmont slopes of the north and west, and it extends through the outer Alburz piedmont to include the southern Caspian coastlands. Climatically, it is fundamentally part of the general Middle Eastern regime, as Iran has wider extremes than are experienced in many other countries of that region. Besides the settled communities there are important groups of nomads and semi-nomads in Iran. In recent times cupidity aroused by Iran's richness in petroleum made this richness a political liability rather than an asset. If we seek to define Iran's function as a state and as a human grouping in terms of a personality, then the country can be said to generate, to receive and transmogrify, and to re-transmit.