Overprinted in color in the field, this World War I map shows the Allied front line at the Ypres Salient on December 2, 1917. The notorious Battle of Passchendaele (also seen as Passendale) began in July 1917 and culminated in the capture by British and Canadian forces of the village of Passchendaele (West Flanders, Belgium) on November 6. Even though the battle had ended some weeks earlier, an action took place on the night of December 1−2 in the areas to the north and east of Passchendaele village shown on the map. Apart from the German defenses (in red), the most notable features of the map are the blue-shaded areas. They mark the extensive wet and waterlogged areas facing the front. Exacerbated by poor weather and the devastation of the ground by the intense artillery bombardment, these conditions had hampered the Allied advance. The confused and fluid nature of the terrain was such that the strong blue line marking the front is only an approximation. No further British advances would take place at Passchendaele, and the gains made would be lost to German advances in the following spring.