'IRAQ AND THE PERSIAN GULF' [‎171r] (346/862)

THE CLASSICAL PERIOD 237
startling successes were made possible because the Persian armies
had broken through the fortress ring and could exploit their mobility.
They anticipate and partly explain the equally rapid expansion of
Moslem power twenty years later. The Christian world, shocked
by the sack of Jerusalem and the loss of the Holy Cross in 614,
gathered its strength. The Emperor Heraclius between 622 and 626
drove the Persians out of Asia Minor and Armenia. In 627 he invaded
Mesopotamia from the region of Urmia, crossing the Zagros into
Assyria. Though unable to take Ctesiphon he made a successful
withdrawal across the Zagros back into Armenia in the midst of
winter. A peace of exhaustion ensued between Byzantium and Persia,
and within ten years both Byzantine Syria and Persian Mesopotamia
had fallen to a new and totally unexpected enemy s the Moslems from
north-western Arabia.
Arab Tribesmen
In this period the Arab principalities of the Jazira and the desert
west of the Euphrates played a part which foreshadowed the develop
ment of the Moslem empire. These Arabs were descendants of the
Aramean tribesmen of the Assyrian period, but included an infiltra
tion of tribesmen from southern Arabia akin to the later Moslems.
By the sixth century both Arameans and Arabs proper had mostly
adopted either Christianity or Judaism as their religion. Earlier
Palmyra was the most notable of these small kingdoms. Others were
Osrhoene with its capital at Edessa, and in the Parthian period Hatra,
a fortress in the Jazira south of Singara, of which there still remain
notable ruins. In the Sassanid period the control of the desert south
of the Jazira fortresses was in the hands of the Lakhmid shaikhs of
Hira (in the desert not far from Najaf, fig. 14, v), who were subject-
allies of the Persians. The Byzantines likewise were confederate
with the Ghassanid chiefs of Transjordan Used in three contexts: the geographical region to the east of the River Jordan (literally ‘across the River Jordan’); a British protectorate (1921-46); an independent political entity (1946-49) now known as Jordan (Arabia Petraea). 1 These
two dynasties were continually warring together, nominally on be
half of their suzerains, during the fourth and fifth centuries a.d.
But about a.d. 600 their power had been divided among a number
of sub-kings with greatly diminished or disunited forces at their
command.
Religion
The clergy of the Mazdaean Church were divided, under their
supreme head, the Mobadhan Mobadh, into the high dignitaries
1 See Geographical Handbook of Palestine and Transjordan Used in three contexts: the geographical region to the east of the River Jordan (literally ‘across the River Jordan’); a British protectorate (1921-46); an independent political entity (1946-49) now known as Jordan , B.R. 514, pp. 446-7.