Which C.S. Lewis book was first published in 1933 as an allegorical spiritual autobiography?

C.S. Lewis’s 1933 allegorical spiritual autobiography was The Pilgrim’s Regress.

The book was Lewis’s first published work after his conversion to Christianity and was subtitled An Allegorical Apology for Christianity, Reason and Romanticism. Its title deliberately echoes John Bunyan’s The Pilgrim’s Progress, but Lewis’s story follows a modern character named John as he travels through a landscape representing competing ideas and beliefs.

Lewis used the book to explore his own movement from atheism toward Christianity. The allegory includes figures and places associated with philosophy, politics, psychology, and religion. Because its references can be demanding, Lewis later acknowledged that the book was not as accessible as some of his other apologetic works.

The Pilgrim’s Regress is distinct from Surprised by Joy, Lewis’s nonfiction autobiography published in 1955. It is also earlier than Mere Christianity, which developed from wartime radio broadcasts.