The reason for the conquest of Sindh by Ummayyad Imperialism was Raja Dahir's refusal to return Muhammad Bin Allafi, who had taken asylum under Raja Dahir's government. As it was against the social rule of the Sindhis in those days, to return the parsons who had placed themselves under their protection from their enemies. Raja Dahir's tolerance and liberal minded-ness was a well known fact, or account of which people of various religions lived peacefully in Sindh, where Hindus had their temples and Parsis had their fire temples, Buddhists had their pagodas, Muslims had their mosques. The Muslims had settled in Sindh on account of the policy of the Arab rulers. These rulers had difference with the relations of the Prophet, and being intolerant, wanted to kill them. How could this God-fearing ruler return these sheltered people to the cruel and tyrant Arab rulers? It is said that Imam Hussain (Alahisalam), after being harassed by Yazeed and his followers, wanted to come to Sindhi on the invitation of Raja Dahir. But instead of being given permission to go to Sindhi, he was martyred at Karbala. The fact is that the Arab Imperialism started during the days of Umer, who had started conquering other countries. This was the fifteenth invasion of Sindh. How in the days of Waleed Bin Abdul Malik, the Arabs succeeded. It will be proper if I elaborate on the fourteenth invasion of Sindh, since the days of Caliph Umer.