The book presents the first integrated study of the relationship between official Islamic leadership (muftiship), non-official Islamic authorities, grassroots Muslim communities and the state in post-Communist Eurasia, encompassing Lithuania, Belarus, Ukraine, the Volga-Urals, Crimea, the North Caucasus, Azerbaijan and ex-Soviet Central Asia. Its analysis is positioned within the current secularism/de-secularisation debate. The book is based on a wide range of primary and secondary sources, including the author’s interviews with Islamic official and popular leaders and authorities, which she conducted over two decades in various parts of Eurasia. The book employs a history-based perspective and compares the nature and role of official Islamic leadership and the state-Muslim relations across Eurasia with those in both the Middle East and Western Europe. It argues that in most of the post-Soviet lands, the official Islamic leadership and its relations with the state have largely retained their particular national and broader Eurasian character, which distinguishes them from what prevails in the Middle East and Western Europe. At the same time, the increasing political ’Europeanisation’ of Lithuania and Ukraine since 2014 and, to some extent, Belarus, has accounted for their divergence towards the Western model of state-Muslim relations. In conclusion, it analyses the impact of globalisation and the advance of global Salafism, in particular, on Islamic leadership and state-Muslim relations across post-Soviet Eurasia.