The Battle of Verdun, was fought from 21 February to 18 December 1916 on the Western Front. The battle was the longest of the First World War and took place on the hills north of Verdun-sur-Meuse in north-eastern France. The German 5th Army attacked the defences of the Fortified Region of Verdun (RFV, Région Fortifiée de Verdun) and those of the French Second Army on the right (east) bank of the Meuse. Using the experience of the Second Battle of Champagne in 1915, the Germans planned to capture the Meuse Heights, an excellent defensive position with good observation for artillery-fire on Verdun. The Germans hoped that the French would commit their strategic reserve to recapture the position and suffer catastrophic losses, at little cost to the Germans.
Poor weather delayed the beginning of the attack until 21 February but the Germans captured Fort Douaumont in the first three days. The advance slowed in the next few days, despite inflicting many French casualties. By 6 March, twenty and a half French divisions were in the RFV and a more extensive defence in depth had been constructed. Pétain ordered there to be no retreat and that the Germans were to be counter-attacked, despite this exposing French infantry to German artillery-fire. By 29 March, French guns on the west bank had begun a constant bombardment of Germans on the east bank, causing many infantry casualties. The German offensive was extended to the left (west) bank of the Meuse, to gain observation and eliminate the French artillery firing over the river but the attacks failed to reach their objectives.
In early May, the Germans changed tactics again and made local attacks and counter-attacks; the French recaptured part of Fort Douaumont but a German counter-attack ejected the French and took many prisoners. The Germans resorted to alternating attacks on either side of the Meuse and in June captured Fort Vaux. The Germans advanced towards the last geographical objectives of the original plan, at Fleury-devant-Douaumont and Fort Souville, driving a salient into the French defences. Fleury was captured and the Germans came within 4 km (2.5 mi) of the Verdun citadel but in July, the offensive was cut back to reinforce the Somme front. From 23 June to 17 August, Fleury changed hands sixteen times and an attack on Fort Souville failed. The offensive was reduced further but deceptions were tried to keep French reinforcements away from the Somme. In August and December, French counter-offensives recaptured much ground on the east bank and recovered Fort Douaumont and Fort Vaux.
The battle lasted for 303 days, the longest and one of the most costly in human history. In 2000, Hannes Heer and K. Naumann calculated that the French suffered 377,231 casualties and the Germans 337,000, a total of 714,231 and an average of 70,000 a month. In 2014, William Philpott wrote of 976,000 casualties in 1916 and 1,250,000 suffered around the city during the war. In France, the battle came to symbolise the determination of the French Army and the destructiveness of the war.