ADMINISTRATIVE GEOGRAPHY'Ab din in former Sasanian territory but were extended to include
Amid, R'as 'Ayn, Mayyafariqin, and Maridin in former Byzantine
territoryP
As the most important frontier city on the Byzantine border, Nasibin
was governed by a marzbiin during the fifth and sixth centuries.^23
Although an ostiindiir (M.P., administrator of an ostiin) appears to
have been at Nasibin in the reign of Hurmizd IV (579-90),24 this city
was under a marzbiin in the 590s.^25 Nasibin survived as the major
administrative center in this part of the Jazira after the Islamic con-
quest. As early as 644 Nasibin was governed by an amrr,26 and during
the caliphate of 'Uthman (644-56) the governor ('iimil) of Nasibin
was a subordinate of Mu'awiya when the latter was governor of
SyriaP About 686-87, during the second fitna, Nasibin was governed
for the Marwanis by an amrr called Ibn 'Uthman.^28 After the battle
at the Khazir in 686, Ibdhim ibn Malik al-Ashtar put his brother,
'Abd ar-Ral}.man, in charge of Nasibin.^29 The local Christian Persian
physician called Mardanshah, who helped Mul}.ammad ibn Marwan
take Nasibin in about 694, was rewarded with the administration of
the city.30
The evidence for the administration of most of the districts of this
province in the early Islamic period is rather slim. The most important
change involved the reorientation of the entire province, its attachment
to al-Jazira, and the inclusion of several districts that had formerly
been part of Byzantine Mesopotamia.
ARD MAWSIL
The formation of the province called the land (Ar. arcJ) of Mawsil
by the Arabs is much more complicated. It appears to have been the
result of a process of consolidation during the Sasanian period and
may have been based on the former primacy of the vassal kingdom
of greater Adiabene (Hedhayabh) along the upper Tigris in the Par-
22 Ibn Khurradadhbih, Masiilik, p. 95.
23 Chabot, Synodicon, pp. 526-29, 532-37; Scher, "Histoire nestorienne," 11(1), 176.
24 Hoffrnann, Persischer Miirtyrer, pp. 94-95.
25 Scher, "Histoire nestorienne," 11(2), 515.
26 Guidi, Chronica Minora I, I, 31; 11, 26; Noldeke, "Guidi," p. 34.
27 BaladhurI, Futu/J, p. 178.
28 A. Mingana, Sources syriaques (Leipzig, 1908), I, 183-84.
29 TabarI, Ta'rrkh, 11, 716.
30 Sachau, Rechtsbucher, 11, xiii-xiv.