This new textbook offers the reader an accessible introduction to the study of modern naval warfare, providing a thorough grounding in the vocabulary, concepts, issues, debates and relevant history. The book includes an examination of relevant historical battles and campaigns, including numerous case studies but is not a narrative history of war at sea. Rather, it offers a thematic, debate-driven analysis of the key features of naval warfare and of the interaction of the maritime with the land and air environments informed by, and illustrated with reference to, relevant history. While the focus will remain on activity at and from the sea, the book will reflect on the ‘joint’ (inter-service) nature of most modern naval operations and activities. The main focus of the book will be on modern naval warfare, defined here as warfare in the twentieth and twenty-first centuries. Detailed case studies of key battles and campaigns will be provided to support the analysis, and are accompanied by maps, diagrams and illustrations. Many of these case studies will relate to the activities of the US Navy and the British Royal Navy, but the book also addresses the role and experience of smaller naval forces.The book is divided into two parts. The first focuses on ‘concepts of naval warfare’ and introduces readers to the key concepts and ideas associated with the theory and practice of naval operations. The second part focuses on the conduct of war at sea, and also on peacetime roles for contemporary navies. This section concludes with a chapter that looks ahead to the likely future of naval warfare, assessing whether navies are likely to be more or less useful than in the past. Understanding Naval Warfare will be essential reading for students of naval warfare, seapower and maritime security, and highly recommended for students of military history, strategic studies and security studies in general.