The Battle of Verdun, 21 February-15 December 1916, became the longest battle in modern history. It was originally planned by the German Chief of General Staff, Erich von Falkenhayn to secure victory for Germany on the Western Front. The aim was to crush the French army before the Allies grew in strength through the full deployment of British forces. Without France’s ninety-six divisions the Allies would be unable to continue fighting in the west.
To achieve his aim Falkenhayn needed to target a part of the French front where strategic necessity and national pride combined. The ancient fortress city of Verdun on the River Meuse was just such a place. By securing the heights on the east bank of the river, the Germans would dominate the surrounding area, making it crucial for the French to retake the ground or loose Verdun. Here Falkenhayn planned to use more than 1200 artillery pieces to destroy French units, whilst making limited use of German infantry to minimise his own casualties.
At 4am on 21 February 1916 the battle began, with a massive artillery bombardment and a steady advance by troops of the German Fifth Army under Crown Prince Wilhelm. Five days into the battle, German forces captured Fort Douaumont, the largest and highest of the 19 forts protecting Verdun. The battle appeared to be going Falkenhayn's way. French military leaders declared Verdun could not be held if the east bank of the Meuse was lost and that French national morale would not survive the loss of the city. At this point, however, Crown Prince Wilhelm and his staff stopped following Falkenhayn's strategic concept and committed the Fifth Army to greater offensive action. The seizure of ground became the priority and by the end of February, German losses at Verdun were similar to the French casualties.
General Philippe Petain was then given command of the French Second Army at Verdun. Petain had a reputation as a master of defence and organised his forces to defend in depth by establishing a series of mutually supporting strongpoints, rather than pushing all his troops into the vulnerable front line trenches. Petain also rotated units through Verdun on a regular basis and whilst this exposed much of the French Army to the battle, it ensured troops did not spend long periods of time at the front. The French also greatly increased the number of artillery pieces at Verdun, leading to the Germans suffering equally from incessant shelling. The ability of the French to sustain the battle was due to ammunition and supplies arriving along the 'Voie Sacree', the Scared Way, a single road into Verdun kept open despite constant German shelling.
On 6 March, the Germans renewed their offensive, this time on the west bank of the Meuse. The already terrible battlefield conditions were made worse throughout March and April, as persistent rain turned the area into a quagmire. In late April, General Robert Nivelle took over French command from Petain and began large-scale counter attacks. This offered the Germans a chance to return to Falkenhayn's strategy but by this time all sense of the original concept was lost, replaced by a fixation to take Verdun. In early June the Germans took Fort Vaux after very tough fighting. This proved to be their final success. Efforts to continue the advance later that month failed, despite the use of phosgene gas.
On 24 June, the Allied bombardment began on the Somme. The German offensive at Verdun was reduced in order to reinforce the Somme front. Nivelle seized his chance and attacked. His Second Army had artillery superiority and he employed new tactics based on specialist infantry sections armed with light machine guns, rifle grenades, mortars and light field guns. Even so, the Germans were not prepared to give ground. Casualties rose as villages such as Fleury changed hands several times. There was also terrible fighting for the forts taken by the Germans earlier in the battle before these too fell to the French.
The battle closed down on 15 December, as winter conditions and results of fighting on the Somme made further activity impossible. The French had lost 377,000 men and the Germans 330,000. Falkenhayn's plan to destroy the French army had failed. Even worse from a German perspective, the heavy losses at Verdun combined with even greater casualties suffered on the Somme to create a manpower crisis within the army that would become increasingly difficult to resolve as the war continued.