The ocean is humanity's largest battlefield. It is also our greatest graveyard. Resting in its depths lay the lost ships of war spanning the totality of human history. Many wrecks are nameless, others from more recent times are remembered, honored even, as are the battles they fought, like Actium, Trafalgar, Tsushima, Jutland, Pearl Harbor, and Midway. This book is a dramatic global tour of the vast underwater museum of lost warships. It is also an account of how underwater exploration has discovered them, resolving mysteries, adding to our understanding of the past, and providing intimate details of the life of war at sea. Arranged chronologically, the book begins with ancient times and the warships and battles of the Egyptians, Phoenicians, Greeks and Romans, the Chinese, and progresses through three thousand years to the lost ships of the Cold War. In bringing this violent past to life, James Delgado's approach is informed by scholarship, but it is not academic. Through his insights as an explorer, archaeologist, and story teller, Delgado provides a unique and idiosyncratic history of naval warfare, the evolution of its strategy and technology, and it critical impact on the past. From fallen triremes and galleons to dreadnoughts, aircraft carriers, and nuclear submarines, this book vividly brings naval warfare to life.