This book is the result of a thorough review of existing literature (both academic and grey) and official documents. In-depth interviews with academics, and officials and experts of the organizations complemented the desk-top research. With a view to offering am more systematic analysis, the book includes five distinct cases studies of AU-UN cooperation in peacekeeping (peace operations) and mediation, which are considered as two of the major arenas of the partnership. The five cases fall within the temporal period deemed as the operationalization phase of the cooperation (i.e. since 2006), and were selected following the logic of what is commonly known, often in political science research, as the Most-Different Systems Design. The book is written for policymakers, researchers, and students working on/interested in peace and security challenges and governance in Africa. As an important articulation of this emerging form of governance, the book contributes pertinent analytical insights that help to expound the logic and rationale of increasing interactions between the AU and the UN, primarily driven by mutual resource dependence. Based on the analysis of the different case studies, the book illustrates the preponderance of ad-hoc approaches rather than strategic and operational coherence and coordination. While diverse configurations of interactions between the UN and regional actors are not a uniquely African phenomena, the book further argues that the African experience continues to offer fresh insights into the logic and dynamics of the broader UN-ROs relations. ukryj opis