"العراق والخليج الفارسي" [و‎‎١‎٧‎٢] (٨٦٢/٣٤٨)

THE CLASSICAL PERIOD 239
and into Babylonia, where Ctesiphon became in 410 the seat of the
archbishop (catholicos) of the Syriac Church in the Persian Empire.
Nestorian’ professors of the theological school at Byzantine Edessa,
followers of the theologian Nestorius (c. 430), migrated to Sassanid
Nisibis. There a powerful bishop, Barsumas, persuaded the Sassanids
that Nestorian Christians were more trustworthy than their rival
‘monophysites’ or Jacobites (the main church of Syria) who tended
to side with the Byzantines in time of war. Hence the Church in the
Persian Empire became predominantly Nestorian. These Christians
reintroduced a great part of the Byzantine inheritance of Hellenism
into Mesopotamia, and it was through the Nestorian monasteries
and seminaries that the knowledge of Greek philosophy and science
reached the Moslem Arabs of Iraq.
III. THE ARAB CALIPHATES, a.d. 636-1258
The Moslem Conquest
The rise of Islam and of the Moslem power in Arabia and the con
quest of Syria have been described in detail in other handbooks. 1 The
peoples of southern Arabia had long been pressing northward in
isolated movements and raids, but were never a serious danger to
the Byzantines or Sassanids until Mohammed and his successors
gave them union and leadership, based on religious inspiration and
a certain sense of nationality. Their rapid success, where so many
other barbarian invasions had failed, was partly due to the mutual
exhaustion of the two great empires and partly to the novelty of Arab
methods of warfare. Against the small professional armies and the
fortress system they set the tribal levy and the'razzia. Their extreme
mobility and indifference to the importance of fixed positions baffled
all the military science of the civilized Powers. Politically they
brought lighter taxation, because their standards of living were low,
and religious liberty, because they were indifferent to the rival claims
of Monophysites and Nestorians, Zoroastrians and Manichaeans, and
did not force conversion to Islam upon non-Arab peoples (p. 246).
Hence the subject peoples, both peasants and townsmen, generally
welcomed the change of yokes, while the Christian nomads of mixed
Aramean and Arabian stock in Mesopotamia and the Syrian steppes
felt kinship with the new tribesmen.
1 See Syria, B.R. 513, pp. 124 ff.; Palestine and Transjordan, B.R. 514, pp. 99,
448; also Arabia, B.R. 527.