Which First World War battle did J.R.R. Tolkien take part in?

J.R.R. Tolkien took part in the Battle of the Somme during the First World War.

He served as a second lieutenant in the Lancashire Fusiliers and arrived on the Somme in 1916. Tolkien worked as a battalion signals officer, a role that involved communication between units under extremely dangerous conditions. He became ill with trench fever and was sent back to England in October 1916.

The experience affected Tolkien deeply, although scholars avoid treating Middle-earth as a simple one-to-one allegory of the war. Many of his close friends from school were killed, and the themes of loss, endurance, comradeship, and devastated landscapes recur in his writing. Tolkien later drew on his memories of wartime service when creating the emotional and historical texture of his fiction.