In 711 CE, his kingdom was invaded by the Arab Umayyad Caliphate, led by Muhammad bin Qasim. The invasion was triggered by a pirate raid off the coast of Debal, which resulted in the loss of gifts to the caliph from the king of Serendib (modern Sri Lanka)
Raja Dahir fought bravely against the invaders, but was killed in the Battle of Aror near the Indus River. His wife and other women of his household committed Jauhar (self-immolation) to avoid capture by the enemy. His daughters, Surya Devi and Preamala Devi, were taken as prisoners and buried alive in a wall.
Raja Dahir is regarded as a national hero by some Shia and Sunni Muslims of Sindh, as well as by some Hindus. He is remembered for his courage, generosity and secularism. He is also seen as a symbol of resistance against foreign aggression and religious persecution.