In recent years, an increasing amount of research has argued that the successful transformation of rebel organization into parties is critical to stable post-conflict peace and democratization. However, the process of the transformation of rebel groups into parties is not well understood. Under what conditions do rebel groups transform into parties? Or into something else? What are the causal mechanisms that lead to the "successful" transformation of rebel groups into political parties? Does the transformation of rebel groups into parties actually contribute to political stability and democratization? How does transformation differ from region to region? The chapters in this book directly address these questions, and include a combination of broader theoretical and empirical chapters coupled with several in depth case studies by some of the most notable scholars in the field. It should prove indispensable to students of both civil wars, post-conflict peace, and political parties. This book was originally published as a special issue of Democratization.