n8 II Islam in a global context
military commanders, defeated in one spot, might take their troops to a
distant region and establish a garrison there instead. Accordingly, wher-
ever any Muslims settled, soon whole cadres of Muslim society and
culture were set up, partly through the arrival of immigrants, partly
through conversion of local people - for, on conversion to Islam, any
office was open to a man. In non-Muslim territories, once such cadres
were set up, ruled automatically by the
sharia
law and given inner cohe-
sion through Sufism, only the right occasion had to be awaited for Mus-
lim solidarity to make itself felt as political power. When, then, the
Muslims became the dominant elite in a place, further conversion by the
adventurous or the ambitious naturally followed. Conversion by vio-
lence did occur, mostly contrary to Islamic principles, but it played a
very minor part in the expansion of Islam; it was not needed.
We can now see something of the role Islam played in the Afro-
Eurasian historical complex at large, where even before Islam the Semitic
and Iranian peoples were making themselves felt. Islam, in its religious
ideals and then in its influence on social patterns, reinforced just those
traits of the Irano-Semitic heritage that encouraged egalitarian contrac-
tualism and social mobility. It did so by way of the trans-territorial auton-
omy of the religious community as a total moral society. By denying
legitimacy to alternative social norms, it encouraged the development of
institutions that made it easier for the Irano-Semitic cultural traditions to
be received far and wide in the hemisphere. Able to maintain local and
even international solidarity independent of any particular political estab-
lishment, able to draw at once on the skills and habits of migrants from
the lands from Nile to Oxus and also on the talents and local expertise of
converts everywhere, the Muslims were ready to launch their great ex-
pansion just about the time when, in the tenth century, undermined by
the new social patterns formed in its womb, the early Caliphate was
collapsing. That expansion soon reached into almost every part of the
hemisphere, far beyond the original limits of the Caliphate, and it tripled
the area of Islamdom.
This social flexibility was reinforced by a sophisticated and, above all,
cosmopolitan high culture. Opened up to be reconstituted creatively in
the course of transference into Arabic (and later Persian), the Irano-
Semitic traditions of high culture offered to the restless a rich corpus of
arts and sciences. This built not only on the several Irano-Semitic heri-
tages themselves - including their originally Greek components - but
on whatever seemed most readily exportable in the Indie and even the
Chinese traditions. Thus for a time Muslim astronomers, building not
only on their own Babylonian and Greek heritage but also on Sanskrit