This study examines Sudanese peace agreements from 1972 to 2020, analysing the roots of conflict between the political centre and peripheral regions. The analysis draws on the concept of the legacy of state formation, which has cumulatively shaped historical grievances, primarily through political, economic, and cultural marginalization. The study argues that, since the colonial period, central state policies have concentrated development and power in the riverain provinces at the expense of other regions. This situation led to the emergence of grievance-based movements that later evolved into armed insurgency. Although several peace agreements were concluded between the warring parties, most relied on partial sharing of power and wealth while failing to address the fundamental causes of conflict. Further compounding this failure were a lack of trust among factions, foreign mediator intervention, failure to implement commitments, and the use of such agreements to serve short-term political agendas. The study finds that the failure to sustain peace was a direct consequence of persistently ignoring the legacy of state formation and the absence of structural solutions.