After World War I, multiple challenges to identity manifested in the Middle Eastern region, stressing the failure of the nation-state project and its inability to integrate and absorb a multitude of pre-existing identities. The wave of legitimacy and power contestation rapidly reached the whole Muslim World; from the Maghreb through the Sham and the Ural to South East Asia. Yet, as highlighted in this volume, the Muslim identity in Russia and Indonesia faces very different challenges than in Yemen or Tunisia for example. In this context of identity disintegration, several questions arise: How to preserve the Muslim cohesion when the historical hard core of this community is plagued by contestations? Where does legitimacy go when traditional identity erodes? How to reconstruct this legitimacy when the political and social structures have been overthrown? This e-book is the fruit of the Institute for Middle Eastern and Islamic Studies (IMEIS) third annual conference on the theme “Identity, Legitimacy and Power in the Muslim World”. It gathers insights from academics, analysts and field observers on these questions within a diverse set of national and cultural settings. Doing so, this volume offers a multidisciplinary overview of the current situation of the Muslim World in the context of multi-level identity contestations.