Russia’s Islam is introduced in the present paper as having reached, in the course of time, a state of “symbiosis” with Orthodoxy. A curious symbiosis indeed, must acknowledge the author, long limited to the strictly diplomatic or political sphere, since based on the lasting perception of Islam as essentially, though not definitively alien to Russia’s polity and culture. The great chronological turn is represented here by the rapid professionalisation of missionary activity among Muslims, from the mid-nineteenth century onwards. Another, contemporary element of change, to the author’s eyes, is the slightly later instillation of elements borrowed from E. Renan’s polemical works into a missionary conceptual apparatus inherited from Byzantium. Shifting directly from the late Tsarist era to the present, through the Soviet period rapidly typified by a fusion of some sort between the Church and the state, the author stresses the three mutually opposed attitudes of Russian Orthodox missionary institution in face of the Eurasian Muslim world: two radical ones—whether ‘Islamophobic’ (partly conditioned by the impact of the wars in Chechnya) or ‘Islamophilic’ (deeply influence by the neo-Eurasian trend of the early 1990s)—and a third, official and moderate stance. If the latter refuses for instance mutual proselytism, it still considers Orthodoxy as an essential element of Russian society, and the overall position of the Russian Orthodox Church remains characterised by its closeness and exclusiveness. The Law ‘On the Freedom of Conscience and Religious Association’ adopted in 1997 is mentioned as a telling example of the current distinction between three categories of religion: a primordial one (Orthodoxy), a small amount of privileged confessions (historically attested in Russia: Islam, Buddhism, Judaism), and the undesirable ones (Protestant Churches, among others). From the historical viewpoint, it is perhaps to be deplored that the deep chronological turn represented by the launching of conversion campaigns orchestrated by the state in the 1710s under Peter i is conspicuous by its absence from the author’s narrative. Nonetheless, his lively paper, illustrated notably by illustrative examples from his rich experience as a teacher in an Orthodox Institute, provides interesting and reliable elements for reflection on relations between state and religion in modern and contemporary Russia.