"العراق والخليج الفارسي" [و‎‎١‎٧‎٥] (٨٦٢/٣٥٤)

THE ARAB CALIPHATES 243
as the centre of the Caliphate (p. 30), but Mansur built a capital at
Baghdad, choosing this site ‘because’, he said, ‘it is excellent as
a military camp. Besides, here is Tigris to put us in touch with lands
as far as China and bring us all that the seas yield as well as the
food of Mesopotamia, Armenia, and their environs. Then there is
Euphrates to carry us all that Syria, Rakka, and adjacent lands have to
offer. Alansur s city of Baghdad, which he called Dar as Salam, the
‘abode of peace’, became at once the centre of a remarkable blossom-
ing of civilization which lasted until the Mongol invasions in the
thirteenth century. Politically the glory of the Abbasids did not last
long, but throughout the long Abbasid decline southern Iraq was
the centre of a uniform and progressive civilization which was even
more remarkable than that of the ancient world. The basis of wealth
was world-wide trade and local agriculture. Great attention was paid
to the drainage and irrigation works of Iraq, which now reached their
maximum extension (p- 433 )- This was all the more necessary because
by this period the closing of the three deltas had formed the Great
Swamp on the lower Euphrates below Kufa. Iraq, becoming again
the central province of a great Asiatic empire, was freed from the
border warfare and brigandage which had been constant since the
breakdown of the Seleucid Empire, and enjoyed agricultural pros
perity like that of Babylonian times.
Though the Abbasids retained some form of authority in Iraq down
to 1258, they controlled the eastern Moslem empire only for about
a century, and the reign of Harun ar Rashid (786-809) is traditionally
regarded as the crown of their glory. Since the reign of Mansur the
Iranian Barmakids had become the most influential officers in the
Empire, and under Harun they dominated the state until their
overthrow in 803. Their office, later known as the vizirate, continued
to exist. Being held with unrestricted power, it interposed between
the people and the Caliph. Thus the originally republican and acces
sible Caliphate finally became an absolute monarchy, remote and
inaccessible, like that of the Achaemenids and Sassanids, while the
actual exercise of power tended to be in hands other than those of
the Caliph.
The north African and Spanish provinces soon became indepen
dent kingdoms and even established rival Caliphates. Egypt remained
an Abbasid province till 868, but a century later, as the seat of the
Shia Fatimid Caliphate, became a serious rival of the Abbasid in
wealth and power, and secured control of Syria and Palestine (1001).
In the east the Iranian provinces, beginning with Khorasan in 822, fell