The Battle of Verdun started with a 9 hour German Artillery Barrage using 1220 guns on a 20 kilometer front. The Germans fired nearly 1 million shells during the barrage. All French telephone communications were cut off because of the heavy artillery barrage. As a result, no French reinforcements could arrive and effective command was lost. At 4:00 PM the barrage ended, and as one Corporal recalled, of every 5 men, 2 have been buried alive, 2 have been heavily injured and one is still waiting.
On the second day, the Germans used 96 flamethrowers to weaken the enemy even more, and on the third day, they advanced 2 miles and took 3000 prisoners. On February 24th, the two divisions of the French Army holding the line from Herbebois to Meuse fell, and the Germans broke in. The French positions fell in just 3 hours, the Germans took around 10,00 more prisoners.
Two main forts guarded the city of Verdun, the fort of Douaumont and Vaux. Unfortunately for the French, Fort Douaumont was undefended and empty and the Germans took it without a single bullet being fired.
After the fall of Fort Douaumont, French General, Philippe Petain organized around 20 divisions to counter attack the Germans. The Germans responded with more counter attacks and local attacks. The French took Fort Douaumont on May but the Germans took it back again. Then on June The Germans took over Fort Vaux too. Then the Germans advanced towards Fleury-devant-Douaumont. A French city and the Germans took it.
But then on July, the Battle of Somme was initiated by the British to relieve the pressure from the French. Many German and French troops were transferred to the Battle of Somme. Meanwhile, Fleury-devant-Douaumont, had changed hands from the French to the Germans and vice-versa 16 times from July 23 to August 17 1916.
Eventually, from September to December, French counter attacks recovered a lot of ground and also recovered the Forts. The Battle lasted for 302 days and taking many lives.