Lessons drawn from experiences in design and implementation of peace agreements, while varying from one context to the next, can be valuable in negotiation and mediation processes. This policy brief considers three key lessons regarding international support for peacemaking, political participation, and the centrality of victims in peace processes. Presented in The Battle for Peace by Nobel Peace Laureate and former President of Colombia Juan Manuel Santos, the three lessons highlighted here are based on the negotiation and design of Colombia’s 2016 Final Accord. They are evidenced by research data collected by the Peace Accords Matrix’s Barometer Initiative throughout its mandate as implementation monitor of the Colombian agreement. These lessons for conflict parties, negotiators, mediators, and policy makers are applicable far beyond the Colombian case to scenarios in which peace is on the horizon.