Above: French soldiers crawling through their own barbed wire entanglements as they begin an attack on enemy trenches. April-June, 1916. The battle raged from 21 February to 18 December 1916; 9 months, 3 weeks and 6 days at Verdun-sur-Meuse, France. Photograph licensed to War History Network.

There have been many fantastic books written on World War I, also referred to as 'The Great War' or the 'First World War'. A few include The Pity of War: Explaining World War I by Niall Ferguson (Basic Books, 1999); Cataclysm: The First World War as Political Tragedy by David Stevenson (Basic Books, 2004); The Great War by Ian F.W. Beckett (Pearson Longman, 2001); The First World War: To Arms by Hew Strachan (Oxford University Press, 2009); and Pandora's Box: A History of the First World War by Jorn Leonhard (Harvard University Press, 2018). 

Above: One of the subsurface chambers in fortified Verdun was used as a hospital. The little dog in the foreground refused to be separated from his wounded master. Photograph licensed to War History Network.

The Battle of Verdun lasted 9 months, 3 weeks, and 6 days. As such, it was the longest battle of the First World War, or World War I. Casualties and deaths were enormous: French forces suffered 379,000 casualties (163,000 dead), while German casualties totalled 336,000, of which 143,000 were killed at Verdun, in the northeastern-most region of France.