The past two decades have seen a decline in the liberal world order; states increasingly move away from peaceful negotiation, justice, and human rights. Instead, they rely on an emerging model of authoritarian conflict management, which depends on excessive violence, coercive negotiations, and hierarchical structures of power to suppress internal conflicts. However, recognising that state coercion is crucial, yet not sufficient, to construct and sustain a long-term order, scholars have recently begun to examine the illiberal peacebuilding practices employed by authoritarian regimes to construct and consolidate postwar order. This is an emerging area of inquiry in which many authoritarian practices and their impacts on local communities remain understudied in the academic literature. Focusing on Syria, ILIBRLSYRIA combines cutting-edge empirical strategy with interdisciplinary approaches to investigate the processes and impacts of novel illiberal peacebuilding practices deployed by the regime to control space and society in areas recaptured from defeated rebel forces. ILIBRLSYRIA is structured around three in-depth and interrelated studies, each focusing on one illiberal practice identified through extensive field observation. These include the remobilisation of former rebels, the diversion of international aid, and the stimulation of refugee migration. The theoretical and empirical findings will provide original insights into the realities and complexities of authoritarian postwar governance in contexts often viewed through the simplistic lens of military victory by incumbent regimes. ILIBRLSYRIA is highly relevant for policy circles. It will offer evidence-based knowledge and contribute to ongoing debates focused on developing strategies to counteract and mitigate the impacts of illiberal peacebuilding, particularly at a time when such practices are on the rise worldwide.