It's the western front, mainly Britain and France against Germany. The battlefield on the western front of World War I began with mobile warfare and then turned into positional warfare. 19 14 In September, the German army was attacked by the French army on the northeast border of France, which was called "19 14 Battle of the Marne" in history, and the German army retreated to the front of the Aina River. At this point, positional warfare began to form in most parts of the western front. By June 1 1, the entire western front had changed from mobile warfare to positional warfare.