This dissertation is a study of the life and work of Zayn al-Dīn al-Khwāfī (d. 838/1435), a Suhrawardī Sufi of Herat active during the late fourteenth and early fifteenth centuries. Besides providing a first detailed biography of Khwāfī, the current study subjects his life to a number of analyses from the perspectives, respectively, of the development of the Suhrawardī and Kubrawī lineages (silsila) and brotherhoods (ṭarīqa); the expansion of Khwāfī’s network into the Mamlūk and Ottoman lands; the role of social and political circumstances in the evolution of Sufi communities; issues of controversy, divergence and differentiation among Sufi groups; and, finally, Khwāfī’s contribution to Sufism and religious traditions, in his time and beyond. The research is based on an array of contemporary sources, ranging from hagiographical sources, Khwāfī’s own works, and independent chronicles, in Persian, Arabic, Turkish and Chaghatai to a limited number of modern studies, the criticism of which is a main concern of this dissertation. The body of the dissertation, aside from the introduction and conclusion, consists of eight chapters, divided into two parts. Part I considers Zayn al-Dīn Khwāfī’s biography in five chapters, starting from his early formation in Herat until his return there at the end of his life. In these chapters, I examine his sources of influence, his spiritual lineage, the networks among religious and political notables, and the community he built. Part II examines Khwāfī’s path in a broader manner and is divided into three chapters. The first chapter is devoted to the study of the spread of his path to Ottoman Anatolia and is, in fact, an extension of Chapter IV. The next two chapters deal with Khwāfī’s works and thought. Some of the important questions dealt with here are related to the spiritual handshake, dream interpretation, Sufi worship, and perspectives on Muḥyī al-Dīn Ibn ʿArabī (d. 638/1240).