This book offers the first comprehensive analysis and comparison of all the EU High Representatives / Vice Presidents of the Commission (HRVPs) until 2024. The book explores how three incumbents with very different backgrounds, ways of working and personalities took up the challenge of formulating the EU's answers to brewing international crises, regional instabilities, humanitarian disasters and, eventually, war. Applying role theory, the research provides deep insights into foreign policy leadership during a period when the EU needed to adapt to a rapidly changing international environment. Based on a large set of expert interviews, the book makes the case that the leadership and role performance of the HRVP matter and can have a positive impact on the EU's international activities. As geopolitics stages a revival, future HRVPs need to engage powerful member states and key actors in Brussels to unleash the full potential of the EU's economic, political and military weight.