The Great War S01 E05 This Business May Last a Long Time

The Battle of the Marne in September 1914 ultimately proved to be a pivotal victory of the war for Allied Forces, but, at the time, they were not able to exploit it to bring a swift end to hostilities. Instead, both sides encountered the phenomenon of trench warfare. Culminating at Ypres late in 1914, the trench line stretched from the sea to Switzerland.