THE ARAB CONQUEST AND THE COMING OF ISLAM
The power that toppled the Sassanids came from an unexpected
source. The Iranians knew that the Arabs, a tribally oriented
people, had never been organized under the rule of a single power
and were at a primitive level of military development. The Iranians
also knew of the Arabs through their mutual trading activities
and because, for a brief period, Yemen, in southern Arabia, was
an Iranian satrapy.
Events in Arabia changed rapidly and dramatically in the sixth
century A.D. when Muhammad, a member of the Hashimite clan of
the powerful Quraysh tribe of Mecca, claimed prophethood and began
gathering adherents for the monotheistic faith of Islam that had
been revealed to him (see Religious Life , ch. 2). The conversion
of Arabia proved to be the most difficult of the Islamic conquests
because of entrenched tribalism. Within one year of Muhammad's
death in 632, however, Arabia was secure enough for the Prophet's
secular successor, Abu Bakr (632-634), the first caliph and the
father-in-law of Muhammad, to begin the campaign against the Byzantine
Empire and the Sassanid Empire.
Islamic forays into Iraq began during the reign of Abu Bakr.
In 634 an army of 18,000 Arab tribesmen, under the leadership
of the brilliant general Khalid ibn al Walid (aptly nicknamed
"The Sword of Islam"), reached the perimeter of the Euphrates
delta. Although the occupying Iranian force was vastly superior
in techniques and numbers, its soldiers were exhausted from their
unremitting campaigns against the Byzantines. The Sassanid troops
fought ineffectually, lacking sufficient reinforcement to do more.
The first battle of the Arab campaign became known as the Battle
of the Chains because Iranian soldiers were reputedly chained
together so that they could not flee. Khalid offered the inhabitants
of Iraq an ultimatum: "Accept the faith and you are safe; otherwise
pay tribute. If you refuse to do either, you have only yourself
to blame. A people is already upon you, loving death as you love
Most of the Iraqi tribes were Christian at the time of the Islamic
conquest. They decided to pay the jizya, the tax required
of non-Muslims living in Muslim-ruled areas, and were not further
disturbed. The Iranians rallied briefly under their hero, Rustam,
and attacked the Arabs at Al Hirah, west of the Euphrates. There,
they were soundly defeated by the invading Arabs. The next year,
in 635, the Arabs defeated the Iranians at the Battle of Buwayb.
Finally, in May 636 at Al Qadisiyah, a village south of Baghdad
on the Euphrates, Rustam was killed. The Iranians, who outnumbered
the Arabs six to one, were decisively beaten. From Al Qadisiyah
the Arabs pushed on to the Sassanid capital at Ctesiphon (Madain).
The Islamic conquest was made easier because both the Byzantine
Empire and the Sassanid Empire were culturally and socially bankrupt;
thus, the native populations had little to lose by cooperating
with the conquering power. Because the Muslim warriors were fighting
a jihad (holy war), they were regulated by religious law that
strictly prohibited rape and the killing of women, children, religious
leaders, or anyone who had not actually engaged in warfare. Further,
the Muslim warriors had come to conquer and settle a land under
Islamic law. It was not in their economic interest to destroy
or pillage unnecessarily and indiscriminately.
The caliph Umar (634-44) ordered the founding of two garrisoned
cities to protect the newly conquered territory: Kufah, named
as the capital of Iraq, and Basra, which was also to be a port.
Umar also organized the administration of the conquered Iranian
lands. Acting on the advice of an Iranian, Umar continued the
Sassanid office of the divan (Arabic form diwan). Essentially
an institution to control income and expenditure through record
keeping and the centralization of administration, the divan would
be used henceforth throughout the lands of the Islamic conquest.
Dihqans, minor revenue collection officials under the
Sassanids, retained their function of assessing and collecting
taxes. Tax collectors in Iraq had never enjoyed universal popularity,
but the Arabs found them particularly noxious. Arabic replaced
Persian as the official language, and it slowly filtered into
common usage. Iraqis intermarried with Arabs and converted to
By 650 Muslim armies had reached the Amu Darya (Oxus River) and
had conquered all the Sassanid domains, although some were more
strongly held than others. Shortly thereafter, Arab expansion
and conquest virtually ceased. Thereafter, the groups in power
directed their energies to maintaining the status quo while those
outside the major power structure devoted themselves to political
and religious rebellion. The ideologies of the rebellions usually
were couched in religious terms. Frequently, a difference in the
interpretation of a point of doctrine was sufficient to spark
armed warfare. More often, however, religious disputes were the
rationalization for underlying nationalistic or cultural dissatisfactions.
Data as of May 1988