Brigadier-General (later Sir) Herbert Hart left New Zealand in 1914 as a major with the Main Body of the New Zealand Expeditionary Force and returned in 1919 as a much decorated brigadier-general. Initially, Hart served as William Malone?s second-in-command in the Wellington Infantry Battalion. He commanded the Wellington Battalion during the closing stages of the Gallipoli campaign, and then served as a battalion and brigade commander on the Western Front between 1916 and 1918. During this time Hart kept a diary, which is now widely regarded as one of the most important personal sources relating to the New Zealand Expeditionary Force. His service on the Western Front is the principal focus of the diary. Exceptionally well written, it includes gripping descriptions of both combat and life behind the front line and on leave in France and United Kingdom. Only one diary by a New Zealand battalion or brigade commander has previously been published (William Malone?s), and because he was a more senior commander Hart was involved in and comments on a much wider range of issues than are dealt with in that or any other published New Zealand diary. The publication of this edition of Hart?s diary will attract considerable international interest. This important publication will also include an introductory chapter on Hart?s early life, and a concluding chapter about his diverse and distinguished career after the war, including his term as Administrator of Western Samoa from 1931 to 1935.