Trench warfare Even though the Great War was known as the life and death in the trenches, only a small percentage of the army served there. The trenches were the most dangerous places of the front lines. They were the protection for all the things that were going on in the background e.g. Supply lines, headquarters, workshops to name a few. Trenches were built to give protection from the enemy and their weapons. Both sides began digging trenches not only to take cover but to also hold their ground