The author analyses the relationship between jihad and politics in the Samanid period. In this age, the new Persianate dynasties, breaking the political unity of the Caliphate, were obliged, in order to legitimate their power, to behave as actors of the jihad. At the same time, one can observe a shift of the geographical focus of holy war, from the Byzantine frontiers to the Central Asian limes. Driven by the Samanids, the massive conversion of Qarakhanid Turks brought about growing intervention by the latter in the former’s affairs. In response to impulses from the south, the Turks did launch large-scale military campaigns on which most Islamic sources prefer to keep silent. Taking advantage of the inner divisions and seditions of the Samanid realm, they put an end to their rule, opening a lasting era of Turkic domination over the central part of the world of Islam. If D. Tor offers an interesting and innovative approach to this paradoxical consequence of the Samanids’ role as initial promoters of Islam in Central Asia, the reader deplores the rare references to primary sources and the reliance of substantial part of this study on works by modern historians.