Beneath Flanders Fields: The Tunnellers War 1914-1918 by Peter Barton , Peter Doyle, Johan Vandewalle. This is quite simply the best book on the Great War I have read. Profusely illustrated it tells the tell of military mining on the Western Front in amazing detail ranging from poignant witness testimonies, archeological photos to all manner of military and technical detail. Packed with anecdotes this is not a dry list of engagements but a really in-depth look at the British and Commonwealth miners and their German counterparts who fought a highly developed and often brutal war underground. A series of line illustrations are particularly interesting bringing clarity to the subject showing detailed cutaways of tunnel system and the like. Highly recommended.