What was the name of the First World War battle where J.R.R. Tolkien served as a signals officer?

J.R.R. Tolkien served as a signals officer during the Battle of the Somme in the First World War.

Tolkien served in the British Army’s Lancashire Fusiliers and was commissioned as a second lieutenant in 1915. In 1916 he went to France and took part in the Somme offensive, one of the war’s largest and bloodiest campaigns. His duties included work as a signals officer, helping maintain battlefield communications.

Tolkien became ill with trench fever and was sent back to England in October 1916. Many of his fellow officers were killed, and the experience affected him deeply. Scholars and readers have discussed possible echoes of the war in his fiction, but Tolkien generally resisted simple one-to-one interpretations of Middle-earth events. The Somme was a real historical campaign, whereas battles such as the Battle of the Pelennor Fields belong entirely to Tolkien’s invented history.