In this long synthesis article the author has tried to provide to a large readership a glance at the innovations brought about in the 1990s in the historical study of Islam in varied regions of Central Eurasia, enhancing the mutual exchanges between these regions. Stressing first the unity and diversity of Central Eurasian Islam, the author evokes the specificities of the Hanafi rite (madhhab) and the relations between the nomadic and the sedentary worlds—a key issue of research during the past two decades. A second chapter on the history and memory of conversion deals first with the issue of how to date the conversion of a population to Islam, according to different kinds of sources, before treating the initial implantation of Islam in the Caucasus and in Central Asia; the reactions in the oases and in the steppe. The chapter on the conversion of northern Central Asia notably evokes the pagan dominance under the Qara Khitai (with its paradoxical impact on the enhancement of the status of scholars of Islam) and the specific role of the khwaja lineages in the Islamicisation process. A specific chapter on the Mongol period and its aftermath deals first with the relations between the shari‘a and the yasa, before stressing the role of Sufism in the continuation of the Islamicisation process, the durable opposition between the notions of jihad and of “salt duty (tuz haqqi),” the role of the mystical paths in modern time, and the permanent development of the veneration of holy places. A chapter on Islam and politics since the eighteenth century questions the notion of dar al-islam when applied to Imperial Russia, evokes successively: the confrontation between Orthodox Christian and Islamic proselytisms in the northern part of Central Eurasia; the first Islamic revivals of the eighteenth-nineteenth centuries; the problematic of political and cultural modernisation in Central Asia; the expansion of ‘Jadidism’ in European Russia; the question of Russia’s citizenship. The Soviet period is treated through the 1917-20 experiences of autonomy and independence, the vicissitudes of institutional Islam, the rich posterity of reformist thought in the twentieth century, and the successive challenges imposed over mystical paths. A last chapter on the last two decades since the launching of Perestroika tackles successively the import of foreign models, the Iranian strategies and the case of Azerbaijan, the Soviet roots of the Party of the Islamic Revival created in Astrakhan in 1990, the experimentation of “Euro-Islam” under the aegis of the political authorities of the Volga-Ural region, the practices of Islam in Russia nowadays. A sub-chapter is devoted to the Caucasus with paragraphs on Dagestan as a source and Chechnya as a field of political Islam, on the confrontation of the mystical paths and the ikhwani trend in Dagestan, on the expansion of autonomous “communities of Muslims” in Dagestan, on the development of the jihadist movement in Chechnya and the expansion of radical Islamist trends throughout the Caucasus. As to Central Asia, the author depicts the varying political fortune of the Party of the Islamic Revival, the emergence of the “communities of Muslims” in Uzbekistan (through the case of the Akramiyya), the mutual concurrence of Islamism and nationalism in Tajikistan, the public debates on the valuation of “community” traditions, and the place devoted to women in the ongoing religious and political processes. In his conclusion, the author notably insists on the necessity to take into account the specificities of contemporary history in the study of the varied forms of Islamicisation process that can be observed since the late 1980s in different regions of Central Eurasia (stressing for instance the impact of a collective memory of the forced migrations of the 1940s to 1960s, as far as large populations of Chechnya and Tajikistan are concerned).