Which First World War battle did J.R.R. Tolkien survive while serving in the British Army?

J.R.R. Tolkien survived the Battle of the Somme while serving in the British Army during the First World War.

Tolkien was commissioned as a second lieutenant in the Lancashire Fusiliers in 1915. He served on the Western Front in 1916 and took part in the Somme offensive, one of the largest and deadliest campaigns of the war.

He later developed trench fever and was sent back to England for treatment. His wartime experiences, including the loss of close friends, became an important part of the background often discussed in relation to the bleak landscapes, fellowship, and industrial destruction in his fiction.

Tolkien did not claim that Middle-earth was a direct allegory of the First World War. He repeatedly resisted one-to-one allegorical readings, although his military experience inevitably informed his imagination and emotional understanding of conflict.