A Pilgrim

Chachnama(Arab account of conquest of Sind)

Chach- Brahmin Ascetic

Queen of Sind(one of the province of present day Pakistan) falls in love with Chach and upon death of King of Sind, gets all relatives slaughtered and got Chach made King.
Deceased King’s brother from nearby kingdom challenges Chach for one-one combat, Chach tells him that, “I am a brahmin, Brahmin do not fight on horseback”. Hearing this, brother of deceased King’s brother dismounts and taking advantage of which, Chach jumps on the horse and cuts off his head.

After ruling for some 40 years, upon death of Chach, his brother took over but was soon succeeded by son of Chach. Son of Chach was Dahir. One interesting fact about Dahir, mentioned in the same book(Naipaul’s Beyond Belief), was the story: when he was told by some famous astrologer that husband of his sister will rule Sind, Dahir married his own sister(must have been symbolic marriage though)!!
By the end of seventh century, Hajaj became governor of “Iraq, Hind and Sind”- Hajjaj was paternal uncle of Muhhamad bin Qasim, he sent Qasim to conquer Sind. Qasim failed once but then with persistence managed to defeat and kill Dahir.

Rest of the account taken from wiki:

The account from the Chachnama narrates a tale according to which the during Muhammad bin Qasim s governorship, the daughters of Dahir were taken captive and were sent on as presents to the Khalifa for his harem. The account relates that they then tricked the Khalifa into believing that Muhammad bin Qasim had violated them before sending them on and as a result of this subterfuge, Muhammad bin Qasim was wrapped in oxen hides and returned to Syria, resulting in his death en route from suffocation. This narrative attributes the motive for this subterfuge to securing vengeance for their father’s death. Upon discovering this subterfuge, the Khalifa is recorded to have been filled with remorse and ordered the sisters buried alive in a wall.