Using critical ethnography and participatory research methodologies, this thesis elucidates the conundrum in the peacebuilding literature, namely, why hybrid peace formation is characterised by tensions, dilemmas and paradoxes that are produced and subsequently reproduced due to the complex interface between the liberal peace and extant power in conflict-ridden polities. Drawing from intensive fieldwork in Mindanao, which has a complex political order, this thesis demonstrates that development NGO-led liberal peacebuilding operations are resisted, ignored, distorted and modified because of perceived harmful impacts to the prestige, legitimacy and multi-faceted interests of local strongmen, who dictate the rules of the game in the conflict zone. Warlord politicians have perceived liberal peace interventions as detrimental to their power and interests. Transforming conflict requires the reconfiguration of repressive power structures to create and widen democratic spaces that accommodate the political participation of previously subordinated and largely powerless war-riven civilians. However, this thesis contends that the liberal peacebuilding of NGOs in Mindanao does not lead to emancipation. Evidence suggests that NGOs help strengthen the resilience of political authority and the legitimacy of local strongmen who have the agency to hijack peacebuilding projects. Moreover, this thesis argues that Mindanao is a lucrative theatre of action for development NGOs due to the constant flow of peacebuilding aid. A slow and arduous peacebuilding process, such as the provision of humanitarian assistance and diffusion of liberal-democratic norms, is ideal to sustain the survival of NGOs and their continued relevance as democratising agents in the conflict zone. The main contribution of this thesis to the peacebuilding literature is the detailed and micro-level ethnographic case study of Mindanao, which offers insights about subaltern power and how it impacts the dominant liberal peacebuilding on the ground.