Challenging the view that sufficient gravity is mainly a tool for prosecutorial discretion, this book reconstructs the interpretation of this criterion and argues for its assessment in objective and legally grounded terms. Marco Longobardo expertly examines case law and prosecutorial practice pertaining to situations and cases under Article 17(1)(d) of the Rome Statute of the ICC to inform his criticism of the assessment of sufficient gravity. The book reviews the assessment of sufficient gravity to evaluate the decisions of the Office of the Prosecutor (OTP) and case law of the Chambers. Chapters explore case studies such as the Lubanga and Ntaganda arrest warrants and the boarding of the Mavi Marmara. Combining jurisprudential and international law perspectives, Longobardo analyses the rules of treaty interpretation and applies them as a methodological framework to assess sufficient gravity. Sufficient Gravity before the International Criminal Court is a crucial resource for scholars and students in international criminal law and justice and public international law. This book's scrutinisation of sufficient gravity provides guidance to ICC organs and parties and contributes to the reinforcement of the ICC project. It is also beneficial for practitioners and NGOs working on issues pertaining to sufficient gravity before the ICC.