This book explores the religious interface between the Gulf and South Asia. By “Gulf” the editors mean West Asia, not just the 6-member Gulf Cooperation Council. South Asia has the largest Muslim population of any region in the world—500 million. In the course of Islamisation, which began with the 8th century invasion of Sindh by Muhammad bin Qasim, the region developed a distinct Indo-Islamic Civilisation culminating in the Mughal Empire. While paying lip service to the religious centres in the Gulf, including Mecca and Medina, this civilisation cultivated its own variety of Islam based on Sufism.