JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. BRILL is collaborating with JSTOR to digitize, preserve and extend access to Journal of the Economic and Social History of the Orient.The voracity of a ruling class for taxes is usually patent to even the casual observer, while its interests in commercial, agricultural or industrial enterprises tend to be much less manifest. For instance, the Umayyad caliphs have always been known as having possessed enormous tax revenues, but their successful activities as agricultural entrepreneurs of their castles are only now becoming general knowledge 1). Similarly, it has been accepted wisdom that the crusader kings of Jerusalem and Acre subsisted on a meager tax base, largely cut off from the substantial commercial profits garnered by the Italian merchants. Recent scholarly research, however, has made it increasingly clear that they never relinquished control over the spice trade2). In this article we shall turn to another subject of Middle Eastern history during the classical Islamic period where preoccupation with the military aspects of ruling class politics has resulted in an undue neglect not only of its less visible fiscal but also commercial interests. By "fiscal interests" I mean those interests which underlie military expansion and conquest and relate to matters of taxation, booty and financial incentives. Our subject is the history of the provinces in the Northwest of the 'AbbSsid empire bordering on Byzantium, the so-called Thughitr (lit. "clefts", meaning the frontier lands between Byzantium and the central 'Abbdsid provinces), during the period from 750 to 962/133 to 351. I) Oleg Grabar, "Umayyad 'Palace' and the Arab Revolution", Studia islamica i8 (1963), 5-x8. z) Jonathan Riley-Smith, "Government in Latin Syria and the Commercial Privileges of Foreign Merchants", in Derek Baker, ed., Relations Between East and West in the Middle Ages (Edinburgh, 1973), I09-32. This content downloaded from 194.29.185.216 on Wed, 18 Jun 2014 22:44:17 PM All use subject to JSTOR Terms and Conditions 72 PETER VON SIVERS The period in the history of the Thughbr extending from their establishment by the 'Abbasids sometime after 750/133 to their devastation by the Byzantines in the 95o's/340's has been given good coverage by modern historians, as far as topography and chronology (mostly involving military events) are concerned 3). With this coverage, the historians faithfully reflect the orientation of the Arab geographers and chroniclers to whom every military expedition and raid against the Byzantine infidels was worth recording as a possible prelude to the completion of the great world conquest begun after Muhammad's death. But the Arabic sources are not entirely exhausted by a repetitive recou...