Which 1933 book was C.S. Lewis’s first published novel?

The Pilgrim’s Regress was C.S. Lewis’s first published novel, appearing in 1933. Its full title is The Pilgrim’s Regress: An Allegorical Apology for Christianity, Reason and Romanticism.

The book follows a character named John on an allegorical journey through a landscape of ideas and spiritual choices. Its title deliberately recalls John Bunyan’s The Pilgrim’s Progress, the famous seventeenth-century Christian allegory.

Lewis wrote the book after his return to Christian belief, and its argument reflects his interest in reason, imagination, and the longing he called “Joy.” The novel is more explicitly philosophical than the later Narnia books and has a denser symbolic structure.

It is often confused with Out of the Silent Planet, published in 1938. That later novel was Lewis’s first science-fiction novel and the opening volume of his Space Trilogy, but The Pilgrim’s Regress came first as a published novel.