The division was mobilized as the 5th Infantry Division in August 1914 and sent to the west for the opening campaigns of the war. In 1914 it fought in the Battle of the Marne and the Race to the Sea. It then settled into positional warfare in the trenches along the Somme. It fought in the Battle of the Somme and in the Battle of Verdun in 1916 and in the Second Battle of the Aisne (also called the Third Battle of Champagne) in 1917. In mid-1917, it was sent to the Eastern Front in response to the Russian Kerensky Offensive. In October 1917, the division was transferred to the Italian Front, where it fought in the Battle of Caporetto. It returned to the Western Front in December 1917, and remained there until war's end, participating in the German spring offensive and the Allied offensives that followed. Until being bloodied in the offensives of 1918, the division was rated a first-class division by Allied intelligence.