Soldiers marching beside a river and over a bridge into a shelled Verdun. The Battle of Verdun was fought from February 21, December 18, 1916 during WWI on the Western Front between the German and French armies. An estimate in 2000 found a total of 714,231 casualties, 377,231 French and 337,000 German, an average of 70,000 casualties for each month of the battle. It was the longest and one of the most costly battles in human history; other recent estimates increase the number of casualties to 976,000. Artist Maurice Toussaint, 1919.