The first incursion by the new Muslim successor states of the Persian Empire occurred around 664 CE during the Umayyad Caliphate, led by Mohalib towards Multan in Southern Punjab, in modern day Pakistan. Mohalib’s expeditions were not aimed at conquest, though they penetrated only as far as the capital of the Maili, he returned with wealth and prisoners of war. This was an Arab incursion and part of the early Umayyad push onwards from the Islamic conquest of Persia into Central Asia, and within the limits of the eastern borders of previous
Persian empires.
The first attack of Arabs under Ubaidullah failed. He was defeated and killed, After this, a series of expeditions were sent to conquer an outpost of Sindh, which all ended in failure. Then Hajjaj made elaborate preparation for the attack on Sindh and sent a powerful army under the command of his nephew and son-in-law Muhammad bin Qasim in 711 AD with 6000 horses, 6000 camels, 3000 animals loaded with equipments and a large infantry. Muhammad bin Qasim proceded towards Sindh through Makarana and first conquered Debel where he received fresh reinforcement sent by Hjjaj through the sea.
Sind, a principality on the shores of the Arabian Sea and the lower reaches of the Indus,was invaded from the sea by the Muslims in 711. The sea port of Daibul fell first, thenseveral towns on the banks of the Indus, including Arur, the capital. Finally, in 713, the Arabs took Multan and the conquest was complete. The fall of Sind opened the way to the
markets of Central Asia.