What was the name of C.S. Lewis’s first published book of fiction?

C.S. Lewis’s first published book of fiction was The Pilgrim’s Regress. Published in 1933, it is an allegorical work subtitled An Allegorical Apology for Christianity, Reason and Romanticism.

The book follows a character named John as he travels through a symbolic landscape. Lewis used the structure to explore religious belief, philosophy, reason, desire, and the effects of modern intellectual movements. Its title deliberately recalls John Bunyan’s The Pilgrim’s Progress, one of the major Christian allegories in English.

The Pilgrim’s Regress appeared shortly after Lewis’s return to Christianity, but it is not a straightforward autobiography. The work is more difficult and argumentative than The Chronicles of Narnia, which helped make Lewis widely famous. Readers also sometimes mistake it for his first book overall; his earlier publications included poetry and scholarly writing.