 No important domain in the civilization of Islam remained unaffected by Sufism in this period.Sufism was an important factor in the historical spread of Islam, and in the creation of regional Islamic cultures, especially in Africa and Asia.Recent academic work on these topics has focused on the role of Sufism in creating and propagating the culture of the Ottoman world, including a study of the various branches of the Naqshbandi and Khalwati orders, and in resisting European imperialism in North Africa and South Asia.