C.S. Lewis’s surname was Lewis when he published poetry under the name Clive Hamilton.
Lewis used the pseudonym Clive Hamilton for two early poetry collections: Spirits in Bondage, published in 1919, and Dymer, published in 1926. “Clive” was his given name, while “Hamilton” was a family name connected with his mother’s side of the family. The pseudonym helped separate his early poetic work from his emerging academic identity.
Spirits in Bondage appeared while Lewis was still a young man and reflects the influence of wartime experience, doubt, and literary models. Dymer is a longer narrative poem with a darker, more allegorical character. Neither book was published under the initials by which Lewis later became famous.
A second pseudonym, N.W. Clerk, was used for A Grief Observed, his 1961 book about mourning after the death of his wife Joy Davidman. These pseudonyms can make bibliographies confusing, but both Clive Hamilton and N.W. Clerk referred to the same author.