Passchendaele; Ypres »

The British Passchendaele offensive of 1917 (known as the 3rd Battle of Ypres to some) has the dubious distinction of being the first where mustard gas was used and saw early efforts at strafing infantry from aircraft. Passchendaele/Ypres gives a detailed account of the battle as well as a guide to the battlefield as it is today, backed up by extensive maps and photographs.