This fort was the largest and highest fort on the ring of 19 large defensive works which had protected the city of Verdun since the 1890s. By 1915, the French General Staff had concluded that even the best-protected forts of Verdun could not withstands bombardments from the German 452mm (16.5 in) guns. These new super-heavy howitzers had easily taken several large Belgian forts out of action in August 1914. Fort Douaumont and other Verdun forts were judged ineffective and had been partly disarmed and left virtually undefended since 1915. On the 25th of February 1916, Fort Douaumont was entered and occupied without a fight by a small German raiding party comprising of only 19 officers and 79 men, entering via an open window by the moad. The easy fall of Douaumont, only three days afther the beginning of the battle, shocked the French army. It set the stage of the rest of ta battle which lasted nine months, at enormous human cost. The fort was finally recaptured by three infantry divisions of the second army, during the first Offensive action of the French during the battle of Verdun, on Octber 24 1916. This event brought closure to the battle.