An understanding of terrain has been the mark of a great commander from at least the time of Sun Tzu, and most campaigns can be interpreted and understood from this standpoint. It is the Great War, a war of trenches and dug-outs, of mines and mud, that epitomises the struggles of commander and soldier alike in the prosecution of battle against the obstacles set for them by terrain. This book, based on 25 years of study, takes the geology of northern France and Flanders and examines such issues as: What created Flanders mud? How were the Germans able to dig deep dug-outs to resist the British on the Somme? And, why were the British successful at mine warfare? These and other issues are dealt with in this volume illustrated throughout with maps and photographs.