This paper provides some analytical and historical background to questions of orthodoxy and heterodoxy in Kurdistan. First, it discusses some theoretical questions concerning the applicability of the orthodox-heterodox concept pair, and some attempts at defining Islamic orthodoxy; it emphasizes the need to attend to questions of power, and to take seriously the radical changes between premodern and modern formations of Islam. In a next step, the paper examines religious developments in the Kurdish-inhabited regions of the early modern and modern Ottoman empire. In the nineteenth century, heterodoxy and religious minorities became objects of concern to Ottoman authorities. At the same time, a new rivalry between the Wahhabî and the Khalidiyya-Nashbandî movements appears to have emerged. Questions of orthodoxy and heterodoxy were radically redefined in the new post-Ottoman nation states. This also explains the very different trajectories of religious minorities in modern Turkey and Iraq. As a result, developments like IS, which are often discussed in theological terms of Islamic orthodoxy, may be better explained in terms of modern mechanisms of power, in particular the centralising tendencies of the nation state and the persistent influence of Leninist and Stalinist ideas and tactics
