This course aims at critically exploring the trends relating to the evolving practices of peace building and transitional justice. The students will therefore be given the conceptual framework to understand the dynamics, institutions and actors involved in such settings. More particularly, the course will provide insights on the relationship between peace building and international relations, the accountability mechanisms (truth commissions, amnesties, international and domestic prosecutions) set up to address the commission of international crimes and gross human rights violations and the tools (such as Responsibility to Protect) available to respond to emergency situations. All these dimensions will be contextualized by concrete examples of transitional justice and peace building scenarios, such as Kosovo, Libya or Northern Ireland. The course will conclude with a negotiation exercise where the students can put in practice and test what they have learned in a specific case.