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.