Peter Barton, like so many others, derived his passion for the Great War from his grandfather, who served in a veterinary unit near Ypres, and from veteran friends like Bert Fearns, to whom this book is dedicated. He is a filmmaker and writer, and secretary of the All Party Parliamentary War Graves and Battlefields Heritage Group. Peter Doyle is a geologist - and latterly an archaeologist - with a special interest in the role of geology and terrain in the outcome of battles. Amongst others, he has made studies of the Great War battlefields of the Western Front, Gallipoli and Salonika. With Peter Barton, he is co-secretary of the All Parliamentary War Graves and Battlefields Heritage Group. Johan Vandewalle was born and bred in Zonnebeke. He grew up surrounded by the legacy of the Great War, and many childhood adventures involved things subterranean. Although today a skilled carpenter, his working life began as a professional civil engineer tunneller, and the combined knowledge of both disciplines has created a passion and technical understanding of the underground war which has made him the foremost explorer of the tunnels and dugouts in Flanders. Johan can be found on most evenings at his other business, the Cafe De Dreve on the corner of Polygon Wood, the home of the underground war in the Ypres Salient.