The Royal Marines had the distinction of serving in every major land campaign of the First World War, as well as participating in most minor ones. They also served afloat as an element of the Royal Navy. For the greater part, the morale and esprit de corps of the formation was second to none, wherever its men found themselves and whatever challenges they faced. This new history examines the participation of the corps in actions such as the Defence of Antwerp, the Gallipoli landings, the Battle of the Somme, the Zeebrugge Raid and the Allied intervention in North Russia. It covers the Marines in action aboard ship at the Dardanelles and Jutland, and throws a spotlight on the little-known Royal Marines presence in the West Indies. Flying Marines operated with the Royal Naval Air Service and Royal Flying Corps, often with noted bravery. Wherever possible the words used are those of the men who were there, and these eye-witness accounts (some never before published) offer an immediacy and freshness to this story.