Arab conquest of Sindh

The Umayyad conquest of Sindh took place in 711 AD and resulted in Sindh being incorporated as a province into the Umayyad Caliphate. The conquest resulted in the overthrow of the last Hindu dynasty of Sindh, the Brahmin dynasty, after the death of Raja Dahir.
Although there was no connection between Arabia and Sindh, the war being started was due to events of piracy that plagued the Arabian Sea, at the time the Caliph of the Umayyad Caliphate offered Raja Dahir protection and sovereignty if he would help him in quelling the piracy.
Raja Dahir of Sindh had refused to return Arab rebels from Sindh and Meds and others. Med pirates shipping from their bases at Kutch, Debal and Kathiawar during one of their raids had kidnapped Muslim women traveling from Sri Lanka to Arabia, thus providing a casus belli against Sindhi King Dahir. Raja Dahir expressed his inability to help retrieve the hostages and after two expeditions was defeated in Sindh. Al Hajjaj equipped an army built around 6,000 Syrian cavalry and detachments of mawali from Iraq, six thousand camelry, and a baggage train of 3,000 camels under his nephew Muhammad bin Qasim to Sindh. His artillery of five catapults (manj'neeqs) were sent to Debal by sea.
The first recorded invasion was When Uthman became the third Caliph. He sent a person to obtain intelligence on al-Hind. The Caliph then told him to describe them. He said:
In the year 659 CE, during the period reign of Ali ibn Abi Talib, another expedition under Haras, the son of Marra-l ’Abdí, was sent to conquer Sindh. Initially, the expedition was victorious; he plundered and killed 1,000 men in a day. However, in 662 CE, his men were slain in Kikan. In the year 664 CE, the Caliph sent another expedition under the leadership of Muhallab son of Abú Safra, which was unsuccessful. Chach Nama reports that the Jats of Kikan at the Bolan Pass inflicted a decisive defeat on Muslim forces, killing their commander Haras and forcing a total retreat of invading Muslim forces. This significant setback prompted six subsequent Muslim expeditions over twenty years, five of which failed to establish any lasting presence in Sindh. The Jats' formidable defense, leveraging their mountain terrain, effectively halted Muslim advances into India for two centuries.
Finally al-Hajjaj, then governor of Iraq appointed Muhammad ibn al-Qasim to conquer Sindh with the approval of the Caliph (Abd al-Malik ibn Marwan) and finally succeeded in conquering Sindh. After conquering Brahmanabad in Sindh, Ibn Qasim co-opted the local Brahman elite, whom he held in esteem, re-appointing them to posts held under the Brahman dynasty and offering honours and awards to their religious leaders and scholars. This arrangement with local Brahman elites resulted in the continued persecution of Buddhists, with Bin Qasim confirming the existing Brahman regulation forbidding them from wearing anything but coarse clothing and requiring them to always walk barefoot accompanied by dogs.
The majority of Sindh's population at the time of the Umayyad invasions was Hindu, but a significant minority adhered to Buddhism as well.
Burjor Avari writes that it's likely that Buddhists collaborated and sided with the Arabs before the invasion even began, something that the primary sources describe as well.
Soviet historian, Yu V. Gankovsky, writes that the Arab invasions were only made successful, because leaders of the Buddhist community of Sindh, despised and opposed the Brahmin ruler, hence sympathizing with the Arab invaders and even helping them in times.
On the other hand, Hindu Brahmin resistance against the Arabs continued for much longer, both in upper Sindh and Multan.
The eastern Hindu Jats supported the Sindhi king, Dahir, against the Arab invaders, whereas the western Jats aligned with Muhammad bin Qasim against Dahir. Having settled the question of the freedom of religion and the social status of the Brahmins, Muhammad bin al-Qasim turned against the Jats and Lohanas. Chronicles such as the Chach Nama, Zainul-Akhbar and Tarikh-i Bayhaqi have recorded battles between Hindu Jats and forces of Muhammad ibn Qasim.
Following his success in Sindh, Muhammad bin Qasim wrote to "the kings of al-Hind (India)", calling upon them to surrender and accept the faith of Islam. He dispatched a force against al-Baylaman (Bhinmal), which is said to have offered submission. The Med people of Surast (Maitraka dynasty of Vallabhi) also made peace. Bin Qasim then sent a cavalry of 10,000 to Kannauj, along with a decree from the Caliph. He went with an army to the prevailing frontier of Kashmir called Panj-Māhīyāt (in Western Punjab). Nothing is known of the Kanauj expedition. The frontier of Kashmir might be what is referred to as al-Kiraj in later records (Kira Kingdom in present-day Kangra Valley, Himachal Pradesh), which was subdued.
Bin Qasim was recalled in 715 CE and died en route. Al-Baladhuri writes that, upon his departure, the kings of al-Hind had come back to their kingdoms. The period of Caliph Umar II (r. 717–720) was relatively peaceful. Umar invited the kings of "al-Hind" to convert to Islam and become his subjects, in return for which they would continue to remain kings. Hullishah of Sindh and other kings accepted the offer and adopted Arab names.
The Umayyad conquest brought the region into the cosmopolitan network of Islam. Many Sindhi Muslims played an important part during the Islamic Golden Age; including Abu Mashar Sindhi and Abu Raja Sindhi. Famous jurist Abd al-Rahman al-Awza'i is also reported by Al-Dhahabi to be originally from Sindh.