This book models the impact of UN peacekeeping missions, exploring the variety of diplomatic, geopolitical, and legal functions played by the international UN officials whilst deployed to violent conflicts across the Global South. By adopting a comparative approach to the first armed peacekeeping missions – United Nations Emergency Force (UNEF) deployed in Egypt, Opération des Nations Unies (ONUC) in Congo, United Nations Temporary Executive Authority (UNTEA) in West Papua, and United Nations Peacekeeping Force (UNFICYP) in Cyprus – each chapter traces how organisational interests and racial prejudices shifted from mission to mission, unearthing the granular colonial continuities perpetuated by the field-based staff. Drawing on a wide range of archival material, this book transcends UN headquarters-centred approaches that currently dominate the historiography of international organisations to access the role of mid-level peacekeeping bureaucrats in shaping the post-colonial international order. In doing so, this book traces unexplored continuities between late colonial administrations and the dramatic rise in peacekeeping missions from the late twentieth century onwards. This book illuminates these patterns and ruptures in peacekeeping practices during the formative years of UN peacekeeping and highlights the multifaceted functions played by mid-level UN bureaucrats in shaping the formation of the post-colonial international order.