A member of the Thaqeef tribe, which is still settled in and around the city of Taif, Muhammad bin Qasim's father was Qasim bin Yusuf قاسم بن یوسف)) who died when Muhammad bin Qasim (محمد بن قاسم) was young, leaving his mother in charge of his education. Umayyad governor Al-Hajjaj ibn Yusuf(حجاج بن یوسف) , Muhammad bin Qasim's paternal uncle, was instrumental in teaching Muhammad bin Qasim (محمد بن قاسم)about warfare and governance and was considered by many to be one of his uncle's greatest assets. Muhammad bin Qasim (محمد بن قاسم) married his cousin Zubaidah (ذبیدہ), Hajjaj's daughter, shortly before going to Sindh(سندھ) . Another paternal uncle of Muhammad bin Qasim (محمد بن قاسم) was Muhammad bin Yusuf(محمد بن یوسف) , governor of Yemen (یمن). Under Hajjaj's patronage, Muhammad bin Qasim(محمد بن قاسم) was made governor of Persia(فارس) , where he succeeded in putting down a rebellion. At the age of seventeen, he was sent by Caliph Al-Walid I (خلیفہ ولید الاول)to lead an army towards South Asia into what are today the Sindh and Punjab regions of Islamic Republic of Pakistan (اسلامی جمہوریہ پاکستان).
Reason for attack on Sindh
During those times, some Muslim traders living in Ceylon died and the ruler of Ceylon sent their widows and orphans back to Baghdad. They made their journey by sea with pilgrims. The King of Ceylon also sent many valuable presents for Walid and Hajjaj. As the eight-ship caravan passed by the seaport of Daibul, Hindu pirates looted it and took the women and children prisoner. When news of this attack reached Hajjaj, he demanded that Dahir return the Muslim captives and the looted items. He also demanded that the culprits be punished. Dahir replied that he had no control over the pirates and was, therefore, powerless to rebuke them. On this Hajjaj decided to invade Sindh. Two small expeditions sent by him failed to accomplish their goal. Thus, in order to free the prisoners and to punish the guilty party, Hajjaj decided to undertake a huge offensive against Dahir, who was patronizing the pirates. The another reason for attack was Raja Dahir's policies. As he was oppressive especially towards the down trodden sections of the society. The oppressed classes of Sindh were thus seeing towards the Muslims as emancipators and the Muslims who were entrusted by Allah with the duty to fight against oppression all over the world and to establish a just society, were ready to help the people of Sindh with Muhammad bin Qasim (محمد بن قاسم) against the local ruler was the proof of their feelings about the Muslims.
At Ar-rur (Nawabshah نواب شاہ ) he was met by Dahir's forces and the eastern Jats in battle. Dahir died in the battle, his forces were defeated and a triumphant Muhammad bin Qasim took control of Sindh.
The general populace was encouraged to carry on with their trades and taxes and tributes settled.
Military and political strategy
The military strategy had been outlined by Hajjaj ibn Yousuf(حجاج بن یوسف) When Muhammad bin Qasim invaded Sindh, Hajjaj arranged for special messengers between Basra and Sindh, and told the general never to take any step without his advice. This order was followed to the letter during the campaign. “When you advance in the battle, see that you have the sun behind your backs,” Hajjaj wrote to his cousin just before the famous storming of Debal. “If the sun is at your back then its glare will not prevent you from having a full view of the enemy. Engage in fight immediately, and ask for the help of Allah. If anyone of the people of Sindh ask for mercy grant them aman ( امانsafety and protection), do but not to the combatants (ahl-i-harb اہل حرب), who must all be put to the sword or arrest and imprison them. Whoever does not fight against us, permit them to build the temples of those they worship. No one is prohibited from, or punished for, following his own religion, and let no one prohibit it, so that these people may live happily in their homes.” This edict of Hajjaj bin Yousuf (حجاج بن یوسف)had a lasting influence in the history of Muslim sub continent. By giving the Buddhists and Hindus the status of “zimmis,” and imposing “protection tax” ("جزبہ “jizya”) on them.settle their tribute( اموال amwal) as zimmah .ذمی/ذمہ). responsibility).”
The Arabs' first concern was to facilitate the conquest of Sindh with the fewest casualties while also trying to preserve the economic infrastructure. Towns were given two options: submit to Islamic authority peacefully or be attacked by force (anwattan), with the choice governing their treatment upon capture. The capture of towns was usually accomplished by means of a treaty with a party from among the enemy, who were then extended special privileges and material rewards. There were two types of such treaties, "Sulh" ) صلح peace treaty) or "ahd-e-wasiq (عہد واسق capitulation)" and "aman (امان surrender/ peace)". Upon the capture of towns and fortresses, Muhammad bin Qasim ((محمد بن قاسم performed executions as part of his military strategy, but they were limited to the ahl-i-harb ( اہل حرب fighting men).
After each major phase of his conquest, Muhammad bin Qasim (محمد بن قاسم) attempted to establish law and order in the newly-conquered territory by showing religious tolerance and incorporating the ruling class - the Brahmins and Shramanas - into his administration.
End of Life
Muhammad bin Qasim (محمد بن قاسم) was known for his obedience to the ruler. Walid bin Abdul Malik (ولید بن عبدالمالک)died and was succeeded by his younger brother Suleman (سلیمان) as the Caliph. Suleman (سلیمان)was an enemy of Hajjaj and thus ordered Qasim (محمد بن قاسم) back to the kingdom. Muhammad bin Qasim (محمد بن قاسم) knew of the animosity between the two. He was aware that due to this enmity, he would not be well treated. He could have easily refused to obey the Caliph's orders and declare his independence in Sindh. Yet he was of the view that obeying ones ruler is the duty of a general and thus he decided to go back to the center. His followers wept bitterly, warning him that he was going back to a certain death. We don’t know what he said in reply, if he said anything. We do know, however, that shortly afterwards, he was put behind bars where he died at age of twenty in the prison of Wasit, just before he died he recited an Arabic couplet to the effect: “They wasted me at the prime of my youth, and what a youth they wasted: the one who was a defender of their borders.” He became a victim to party politics. Many historians believe that had he been given a few more years, he would have conquered the entire South Asian region.