ADMINISTRATIVE GEOGRAPHYdistrict into subdistricts. In general, the term ustan (M.P. ostan) was
used for a province, although it might also be used for smaller ad-
ministrative units in certain contexts. Each province was divided into
districts called shahrs (M.P.), each with its district capital or shahristan
(M.P.) and governed by a shahrtj (M.P.) or radh (M.P.). In Sasanian
Iraq the term employed as the equivalent of shahr was kura (pi. kuwar),
which is derived from the Greek chora and had been introduced into
Iraq in the Seleucid period. One of the problems in reconstructing this
system lies in the tendency to confuse the district of the capital of the
province with the province itself.l1 At the lowest level each shahr or
kura was divided into sub districts around small towns or villages.
Such a subdivision was called a tasok in Middle Persian and a tassuj
(pi. tasastj) in Arabic,12 was sometimes equivalent to a rustaq (M.P.
p!. rasat"iq),13 and in lower Iraq might correspond to a canal district.14
Na~iya (Ar.) was also used for this type of unit in some contexts,
although sometimes the presence of a further subdivision at the village
level was recognized by using any of these terms as the subdivision of
one of the others. is Under the Sasanians such a subdistrict was ad-
ministered by a dehtj (M.P.) called a dihqan (pi. dahaqtn) in Arabic.1^6
Subdistricts, and occasionally districts, were also called a'mal (Ar.)
when they served as units of fiscal administration for the collection of
taxes.ARBAYESTANThe province of Arbayestan lying southwest of the upper Tigris had
been reconstituted by Shiipiir 11 in 363 and consisted of territory con-
11 Christensen, Sassanide,s, p. 140; Ebeling, "Frahang-i Pahlavik," p. 9; Lekkegaard,
Islamic Taxation, p. 164; T. Niildeke, Geschichte der Perser und Araber zur Zeit der
Sasaniden (Leiden, 1879), pp. 446-48; Ya'qiibi, Ta'ri'kh, I, 203. R. Frye, Golden Age,
p. 10 gives a slightly different description. According to l:lamza al-I~fahani, the Persians
used kura for part of an ustiin, and the Arabs used it as the equivalent of an ustiin; see
Yaqiit, Buldiin, I, 39.
12 Lekkegaard, Islamic Taxation, p. 164.
13 DinawarI, Akhbiir at-tiwiil, p. 228; Ebeling, "Frahang-i Pahlavik," p. 9; Tabari,
Ta'ri'kh, I, 2165-66.
14 A. Berliner, Beitrage zur Geographie und Ethnographie Babyloniens im Talmud
und Midrasch (Berlin, 1884), p. 47; Altheim and Stiehl, Asiatischer Staat, p. 7.
IS Lekkegaard, Islamic Taxation, pp. 165-66. Lekkegaard (p. 164) says that a tassuj
was divided into rasiiti'q, while Frye (Golden Age, pp. 10, 108) says that a nii~iya/rustiiq
might be divided into tasiisi'j, which goes back to the account of l:lamza cited by Yaqiit
to the effect that each kura was divided into rasiiti'q, each rustiiq into tasiisi'j, and each
tassuj into a number of villages. Mas'iidi (Tanbi'h, p. 40) equates a tassuj with a nii~iya.
16 Christensen, Sassanides, p. 140.