The past decade has been the increasing importance of cooperation between the African Union (AU) and the Regional Economic Communities (RECs) in the areas of peace and security. There have been increased interfaces, synergies and greater levels of involvement of the RECs in the AU conflict prevention, management and resolution agenda and practices. Taking the AU and the Southern African Development Community (SADC) cooperation in peace and security as cases. Against this background, this study focuses on peace and security in Africa, and seeks to understand the interfaces between the AU and the SADC in managing peace and security in Africa during the period 2000-2011. The study specifically focuses on investigating the challenges of coordination and harmonisation facing the AU and the SADC, which will be achieved through analysing peace and security structures, programmes and policies where both entities entwine or diverge, aiming to shed light on such issues. This PhD research project is supervised by Prof. Dr. Ulf Engel and is to be submitted in early 2013.