Recent times have witnessed civilians increasingly becoming the main casualties of violence, often deliberately targeted rather than merely caught up in the midst of the fighting in armed conflicts, leading to an unacceptably high toll on human life and livelihoods of civilians around the globe, and particularly in Africa. The Centre for Human Rights, Faculty of Law, University of Pretoria, with the assistance of the United States Africa Command through the Africa Military Law Forum, on 18 and 19 September 2014 hosted a 'Colloquium on the Protection of Civilians in Armed Conflict', in Pretoria, bringing together over 80 academics, judges, practitioners, policy makers, military personnel, government officials and other commentators. The aim of the Colloquium was to consider the legal, procedural and practical challenges in the implementation of measures to protect civilians in armed conflicts and prevent mass atrocities. Participants examined the notions of the 'responsibility to protect' (and its relationship to article 4(h) of the Constitutive Act of the African Union) and the 'protection of civilians'. They further examined the scope and effectiveness of states' obligations under international human rights law, international humanitarian law, and the law relating to the protection of women, girls, children, internally displaced persons, refugees and other vulnerable populations in armed conflict. This publication, By all means necessary: Protecting civilians and preventing mass atrocities in Africa, consists of the papers presented at the Colloquium, which were subsequently peer-reviewed and reworked, and updated. The Colloquium and this publication were sponsored by the Norwegian Government, through its Embassy in Pretoria.