Why did Trenches Appear?
The first few weeks of the War were ones of mobility, with armies moving back and forth. However, when the Germans realised that their initial attempt to defeat France and Britain would not work they retreated to the high ground and started to dig in and create fortifications.
With the advent of the machine gun, barbed wire, and artillery, warfare had moved in favour of those opting for defensive positions. The sweeping cavalry moves of Napoleonic times were no longer possible and soldiers on the Western Front only had the option of digging in (i.e. creating trenches) to survive.
All along the Western Front (and on other fronts) men created trenches as a means of protection, and as 1914 drew to a close trench warfare had set in.
