World War I claimed the lives of 10 million soldiers and shaped an entire century. Narrated by Academy Award nominee Kenneth Branagh, this extraordinary documentary brings the war's horror and heroism to life in a way never before revealed. Rare archival film—meticulously colourised under the guidance of expert historians—makes the past fresh, relevant, and alive. In addition to these newly reclaimed sights and sounds, surviving WWI veterans share their experiences, personally testifying about life in the trenches, the terror of "going over the top," and the courage and sacrifice of battle. Analysis by military historians, detailed maps, and excerpts from the diaries and letters of men and women in the struggle offer a full range of perspectives on this unimaginably brutal, bloody clash of empires.