According to the Imperial War Museum,
Tolkien was an Oxford University student in 1914 but was commissioned into the Lancashire Fusiliers soon after taking his degree in 1915. He joined the 11th Battalion of his regiment in France in June 1916, shortly before the Battle of the Somme. During the battle Tolkien served as the battalion signals officer. In late October 1916 he contracted trench fever and was sent back to England in early November. He spent most of the rest of the war convalescing. It was at this time that he began to write early versions of his Middle Earth stories. Debate continues regarding the extent to which Tolkienâ€™s war experiences influenced his literary work.