Introduction
THE ethnic diversity of early Islamic Iraq was matched only by its
religious diversity. There were Magians (or Zoroastrians), Jews, Chris-
tians (both Nestorians and Monophysites), pagans, gnostics (including
Manichaeans, Marcionites, and proto-Mandaeans), and Muslims. One
of the most important changes taking place among most of them was
the creation of social divisions along religious lines. Apart from pos-
sible Hellenistic antecedents (e.g., the politeuma), conditions in Iraq
in the late Sasanian period were especially favorable for this trans-
formation. As a result, important precedents were set that are crucial
to an understanding of the nature of the associative society that emerged
by the early Islamic period.
The formation of a society composed of separate religious com-
munities is usually associated with the Muslims and marks a major
change in the social organization of Iraq. This was part of the general
social transformation taking place in southwestern Asia from the fourth
to the ninth centuries. The change produced a society composed of
religious communities, which amounted to social bodies, with their
own legal institutions that sanctioned matters of personal status such
as marriage, divorce, and inheritance. The existence of such com-
munities is fundamental to the formation of Islamic society and serves
as the single most important distinction between Muslim and Hellen-
istic society. The creation of such communities involved both organ-
ization and identity. From a personal point of view, this meant re-
placing means of identification based on language, occupation, or
geographical location with a primary identity based on membership
in a religious community. But such transfers of identity were never as
total or precise as they would seem to be in theory. Although religious
identities often crossed ethnic boundaries, ethnic identities managed
to survive, sometimes because they coincided with religious commu-
nities that gave them institutional form.^1
Several criteria indicate the existence of religious communities in
the late Sasanian period. The first is the spread of a primarily religious
personal identity and religiously sanctioned way of life among Jews,
Magians, and Christians. The religious leaders themselves drew the
ordinary faithful into operating communities of law reinforced by
1 Much of what Barth says about ethnic groups applies equally well to religious
communities. See F. Barth, Ethnic Groups and Boundaries (Boston, 1970), pp. 9-17.