carry on military conquest all over the world.
the north to the valley of the Nile in the south. The successors of Prophet
Muhammad (622–32 AD) were called the khalifas and Abu Bakr was the first
khalifa. Abu and three of his successors (632–661 AD) were known as
Rashidun (Rightly guided khalifas) and then came the dynastic rule of the
Umayyads (661–749 AD), who were replaced by the Abbasids (749–1258
AD). Despite the changes in the ruling families, the khalifa continued to be the
nominal head of the Muslims all over the world. It was during the time of the
Umayyads that the Arabs succeeded in conquering Sind.
Causes for Arab Conquest
    •   The foremost cause was the lure of wealth. The Arabs, having trade
        contact with India from the ancient times, knew that India was a rich
        country. Sind, whose Makran coast played an important role in the
        international trade and which was next to the then Arab empire,
        became their first target.
    •   The religious zeal of the Arabs is also another important cause. Islam
        inspired a warlike spirit and national consciousness among the Arabs.
    •   The desire for territorial expansion is yet another cause. The khalifas
        were not only the heads of Islamic faith but also the heads of the
        Islamic state.
    •   The immediate cause of Arab invasion was, however, the capture of
        certain Arab ships by the sea-pirates of Sind. King of Ceylon sent to
        Hajjaj, the Arab governor of Iraq, some Muslim women. But the ship
        in which they were sailing was captured by the pirates of Debal, a
        sea-port of Sind. Hajjaj demanded from Dahar, ruler of Sind, to set
        free those women. But Dahar replied that he had no control over these
        sea-pirates. Angered by the refusal, Hajjaj decided to conquer Sind
        and sought the permission from Khalifa Walid, who granted it after
        some hesitation.
Course of Conquest and Rule
    •   Hajjaj sent a powerful army under the command of Muhammad bin
        Qasim, in 711 AD. Muhammad proceeded towards Sind and
        conquered Debal. He overran      a few other strongholds. Till then Dahar