The religion Islam was born at Mecca in Arabia. Its founder was Prophet Muhammad. But his teachings made the wealthy people of Mecca his enemies. Therefore, he migrated to Medina in 622 A.D., which was the starting point of the Muslim calendar and the Muslim era called hijra. After eight years he returned to Mecca with his followers. He died in 632 A.D.
The followers of Muhammad set up an empire called the Caliphate. The Umayyads and the Abbasids were called the caliphs. They expanded their rule by conquests and spread their religion Islam. In 712 A.D., Muhammad bin Qasim invaded Sind. He was the commander of the Umayyad kingdom. Qasim defeated Dahir, the ruler of Sind and killed him in a well-contested battle. His capital Aror was captured. Qasim extended his conquest further into Multan. Qasim organized the administration of Sind. The people of Sind were given the status of zimmis (protected subjects). There was no interference in the lives and property of the people. Soon, Qasim was recalled by the Caliph.
However, Sind continued to be under the Arabs. But the Muslims could not expand their authority further into India due to the presence of the powerful Pratihara kingdom in western India. Although the conquest of Sind did not lead to further conquests immediately, it had resulted in the diffusion of Indian culture abroad. Many Arab travelers visited Sind. Indian medicine and astronomy were carried to far off lands through the Arabs. The Indian numerals in the Arabic form went to Europe through them. Since Sind was a part of the Arab empire, the inflow of Indian knowledge was great.