WW1: A rather pensive British laddie caught by the photographer near Mons, undated. Trench warfare was brutal and unforgiving, Hundreds of thousands returned home with what is today identified as Post Traumatic Stress Disorder, yet the literature contains scant information about postwar psychological troubles with violent outcomes. Different times, different people.
When the battle was over, the Allied lines around Ypres formed a salient—that is to say, a bulge, surrounded on 3 sides by the Germans. Movement in and out of the Ypres Salient was hampered by the Yser Canal, which cut across the base of the bulge. Finally, the low-lying terrain was unsuitable for trench warfare. The water table was less than a meter below the surface and, as a result, the troops had to build up walls of sandbags known as breastworks to protect themselves from enemy fire.