Peace and prosperity underpin the success of the Sustainable Development Goals (SDGs): from reducing extreme poverty and violent conflicts to ensuring peaceful and inclusive societies. But there are now more conflicts worldwide than at any time in the past 20 years, spurring massive displacement of millions of people, intensifying livelihood struggles in places such as the Sahel, and reducing opportunities for social cohesion and economic development. Many conflicts are a result of extreme poverty, especially in the Lake Chad region where over 30 million people are in poverty and almost every family is threatened by livelihood insecurity. Without concerted, collaborative action to promote peace and prosperity across the world, violence could drive 100 million people into poverty by 2030. This research is a direct response to this concern. Working in three fragile and conflict-affected Lake Chad territories in Chad, Niger and Nigeria, it will research and co-create locally valid, locally owned and locally sustained peace and prosperity pathways that will serve as decision-support tools to foster sustainable and inclusive development planning in fragile environments. The pursuit of peace and prosperity can involve interconnected social, economic, ecological and governance challenges that entangle competing interests, norms, values, priorities and memories of historical past. As such, research on peace and prosperity pathways must incorporate a diversity of perspectives, worldviews and knowledge systems. Working with partners across the Lake Chad region (which include the University of Differ, University of N'Djamena, University of Maiduguri, and the Lake Chad Basin Commission), the research will (collaboratively) create a system of interlinked research and learning spaces (in the form of Transboundary Citizens Learning Alliances) to reveal the foundations of citizens' preferences and strategies for both socio-economic development ('prosperity') and meaningful and non-violent interactions ('peace'). It will employ a range of interdisciplinary, multi-scale, mixed method approaches (including young citizens panels, participatory scenario-based forecasting and backcasting) underpinned by the principles of knowledge co-creation (such as orientation on societal perspectives, acknowledgement of complex contexts and set of actors, and evaluation on the basis of contextual adequacy with iterative feedback loops). The research brings together science and society in a reciprocally useful way to advance an innovative approach to knowledge co-creation and change-making. While it draws on pertinent research from relevant disciplines, such as conflict, peace, environment, development and ethnography, the focus on co-creation and use of peace-prosperity pathways to refocus development practice - notably in the Lake Chad region - represents a new innovation. The goal of achieving peace and prosperity in the Lake Chad region has enormous economic and political significance for the UK (e.g. continued violence in the region has the potential to trigger youth migration threats in the UK in the longer-term). The research will generate new knowledge, alliances and tools that will foster sustainable peace and prosperity in the region and beyond. New knowledge on the dimensions of, and pathways towards, peace-prosperity will enhance progress towards SDG 1 (poverty reduction) and 16 (peaceful and inclusive societies); all leading to improved lives and livelihood opportunities for citizens. Additional impact will include: development of new knowledge co-creation approaches that can be applied in fragile settings; as well as capacity building of a new generation of young academics in conflict, peace and development research.