Over the 50 years between 1940 and 1990, the countries of eastern Africa were embroiled in a range of debilitating and destructive conflicts, starting with the wars of independence, but then incorporating rebellion, secession and local insurrection as the Cold War replaced colonialism. The articles gathered here illustrate how significant, widespread and dramatic this violence was. In these years, violence was used as a principal instrument in the creation and consolidation of the authority of the state, and it was also regularly and readily utilised by those who wished to challenge state authority through insurrection and secession. Why was it that eastern Africa should have experienced such extensive and intensive violence in the 50 years before 1990? Was this resort to violence a consequence of imperial rule, the legacy of oppressive colonial domination under a coercive and non-representative state system? Did essential contingencies such as the Cold War provoke and promote the use of violence? Or was it a choice made by Africans themselves and their leaders, a product of their own agency? This article focuses on these turbulent decades, exploring the principal conflicts in six key countries – Kenya, Uganda, Sudan, Ethiopia, Somalia and Tanzania.