Chapter E summarises the book's main findings on practices of negotiating and implementing internationalised and legalised peace agreements between state and non-state parties through the lens of international courts' and tribunals' treatment of peace agreements and the Security Council's involvement as an effective third party during the negotiation and implementation of peace agreements. The chapter concludes that it is the involvement of the Security Council based on Chapter VII of the Charter of the United Nations that fosters the internationalisation of what at first glance appear to be intra-state agreements to settle intra-state conflicts between state and non-state parties. However, the book's analysis does not conclude that the parties to internationalised intra-state peace agreements have created international treaties and therewith sources of international law. Instead, Chapter E summarises how state and non-state parties create formalised settlements comprising elements of extra-constitutional, constitutional, international and temporary transitional post-conflict law. Chapter E also points to the future developments of internationalised and legalised peace agreements between state and non-state parties, and proposes questions that could shape future research and approaches to understanding the negotiation and implementation of contemporary peace agreements.