In the aftermath of the Islamic conquests of the seventh and early eighth centuries the territory which came under effective domination of the caliphate extended from the Iberian peninsula and North Africa to Central Asia and into the Persian-Indian borderland of Sind which for three centuries remained its easternmost frontier. Beyond Sind a vast area was left unconquered which the Arabs calledal-Hindand which, in their conception, embraced both India and the Indianised states of the Indonesian archipelago and Southeast Asia. In the countless kingdoms ofal-Hindthe Muslims penetrated, up to the eleventh century, only as traders. By the time that Islamic power was established in North India the political unity of the Abbasid caliphate was already lost. Neither India nor Indonesia were provinces of the classical Islamic state. But in the Middle East three decisive developments had occurred and these created patterns which were to survive the political fragmentation of the empire. Most important was that a thoroughly commercialized and monetised economy with a bureaucracy and a fiscal polity had been established which continued to expand. Secondly, from the ninth century onwards, the Islamic military-bureaucratic apparatus had begun to be staffed with imported slaves on an extended scale. And thirdly, from its Arab roots the Islamic conquest state had shifted to a Persianised foundation, adopting Persian culture and the Sassanid tradition of monarchy and statecraft.