To understand what was trench warfare and why the Great War devolved into one of the vilest forms of fighting one needs to take a look at how the opening of the war evolved in August of 1914 [see my previous blog “How and Why Did WWI Begin?”]
What was trench warfare? Simply put, as the Schlieffen Plan was implemented by Germany when attacking France via Belgium, the Germans were outflanking the French on the left as seen below. Once the French realized that they were being outflanked, they tried to outflank the Germans right flank. Each time both sides realized they might be outflanked, they tried to outflank the enemy. These two armies would eventually run out of land to outflank each other when they came to the English Channel. This became known in history as the Race to the Sea (see map below).