This chapter addresses the law of naval warfare narrowly defined - that is, international humanitarian law which applies to armed conflict at sea. It begins with a brief assessment of the way in which uniquely maritime thematic concerns have influenced the development of the law of naval warfare, focusing upon two of these as indicative examples: the oceans as the venue of armed conflict at sea, and the overt 'stakeholder' status of maritime trade and commerce as an influence upon the development of the law of naval warfare. The chapter then progresses to an account of the major instruments, cases and soft law sources of the law of naval warfare. This is followed by an analysis of those 'means and methods' issues which are generally unique to the law of naval warfare, but remain of enduring utility - issues such as blockade, visit and search, and naval mine warfare. This chapter focuses upon the historical development of the LONW, rather than its likely responses to these many current and future challenges.