The article explores the implications the rise of the ‘Islamic State’ (IS) had on the international order and the salafi-jihadi movement. The main argument is that at the height of its activity (2014–2016) IS was a de facto revolutionary state. In this capacity, IS challenged the international order because contrary to revolutionary states in the past it negated the foundations of the Westphalian system. At the same time, the rise of IS had a tremendous impact on the jihadi (sub)system, as it initiated a period of fragmentation and alliance-building. The competition between IS and al-Qaeda for the hegemony of the movement did not revolve around direct fighting as much as efforts to outbid the rival group. One of the main conduits of this competition was the ‘war of bay’as (pledges of allegiance)’, which consisted of competitive oaths of allegiance from local jihadi forces to one of the two groups. In local contexts, the ‘war of bay’as’ increased tensions and factionalism within jihadi groups, as splinter groups decided to side with the new revolutionary foco. The fragmentation of local jihadi groups unfolded along pre-existing cleavages, grievances and resource-related motivations, increasing the levels of violence and complexity in these local conflicts.