The breadth and depth of the scholarship of Marise Cremona is honoured in this collection of essays written by her colleagues and friends. Taking Cremona's field-defining research as a point of reference, this collection of research articles examines the power of law in EU external relations. Echoing the expansive scope of Cremona's intellectual enquiries across the growing and diversifying field of external relations law, this volume offers new insights into the principles and procedures that underlie this area of law; the role and responsibilities of the EU as an international actor; and the strategies and instruments through which the Union pursues its external agenda. Spanning the analysis of foundational concepts and more contemporary interventions in respect of the environment, human rights, foreign direct investment and even Brexit, what emerges from this collection is a richly conceptualised and clear examination of the multiple ways in which the power of law captures or eludes the EU's construction of a domain of external relations; a domain in which the EU interacts not only with its Member States but also other subjects of the international legal order.