The 'Hundred Days' campaign of 1918 remains a neglected aspect of the First World War. Why was the German army defeated on the Western Front? Did its morale collapse or was it beaten by the improved military effectiveness of a British army which had climbed a painful 'learning curve' towards modern combined arms warfare? This revealing insight into the crucial final months of the First World War uses state-of-the-art methodology to present a rounded case study of the ability of both armies to adapt to the changing realities they faced. Jonathan Boff draws on both British and German archival sources, some of them previously unseen, to examine how representative armies fought during the 'Hundred Days' campaign. Assessing how far the application of modern warfare underpinned the British army's part in the Allied victory, the book highlights the complexity of modern warfare and the role of organisational behaviour within it.