This book presents a systematic, in-depth, and comparative analysis of the role of the EU in the process of international state-building and is one of the first comprehensive books to do so at an international level. Taking the case of Kosovo, it examines the EU’s role in the birth of a state in comparison to other international actors from 1999 to 2008 and moves on to analyse the EU’s role in norm diffusion in the post-independence period (2008–2020).