In this memoir spanning nine decades, Lieutenant Colonel C.F. Jerram (1882–1969) of the Royal Marines recounts his life and military service through both world wars. Jerram describes in candid detail his late 19th-century childhood in Devon and Cornwall, the late Victorian and Edwardian Royal Navy, the Royal Navy’s Far East Station, a traditional Corps of Marines, the Gallipoli Campaign, the World War I Western Front and the interwar and World War II years. His experience and insight convey two fundamental lessons: “Know thy profession and look after those for whom you are responsible.” An essay by the editor, based on other sources, provides a broader perspective on Jerram, whose approach to professional military service is still pertinent today.