'IRAQ AND THE PERSIAN GULF' [‎170v] (345/862)

HISTORY
Wars with Romans and Byzantines
Sapor I, the most aggressive of the early Sassanids, was checked
in the west by the Arab merchant-prince of Palmyra, Odenathus,
who in a time of Roman weakness built up a strong principality in
the Syrian steppes and drove Sapor out of Syria (262, 267). The
Persian Empire thus was unable to break westwards out of Mesopo
tamia at this time, and warfare tended to be limited to the northern
Jazira, where the strong Roman fortifications and castles, based on
Edessa, Nisibis, Singara, and Circesium, 1 imposed a warfare of siege
and position in which the rest of Mesopotamia suffered little.
Occasionally the Romans took the offensive and endeavoured to
imitate the campaigns of Trajan by overrunning all Mesopotamia
and capturing Ctesiphon. None of these attempts achieved per
manent success. The most famous was that of the Emperor Julian
in a.d. 363. To overcome difficulties of supply his army took the
road along the Euphrates, accompanied by a large fleet of river-
craft which used the Nahr Malik to reach the Tigris below Ctesiphon.
Even so, the expedition could not maintain itself and retired north
ward by the Tigris to Roman Mesopotamia. Julian was killed en
route, and his successor Jovian, harried by light Arab forces, was
compelled to surrender the eastern part of the Roman Jazira, includ
ing the great fortresses of Nisibis and Singara. This opened to the
Persians direct routes into Armenia up the Tigris valley, and hence
forth the wars of the Byzantine (Roman) Empire and Persia were
often fought out in Armenia. There the rival churches of the two
empires were struggling for predominance, and the control of the
Caucasian tribes was a major issue. The wars had no final issue and
agreement about frontiers was gradually established, so that in the
fifth century the two empires were on peaceful terms for a long
period of over eighty years.
In the sixth century border warfare was resumed in Mesopotamia,
and a powerful Persian king, Chosroes I (a.d. 53 i- 579 )> revived the
claims of Ardashir and Sapor I to Byzantine Syria. This new aggres
sion was accompanied by religious intolerance and the enforcement
of orthodoxy in both empires. It culminated in the great offensive
of Chosroes II, who (between 603 and 619) captured the Byzantine
fortresses of the western Jazira, crossed the Euphrates, took all the
Byzantine provinces from the Taurus to Egypt, invaded Asia Minor,
and threatened Constantinople itself. Militarily these rapid and
1 Modern Urfa, Nusaybin or Nisibin, Sinjar and Meyadin respectively.