Which C.S. Lewis autobiography recounts his conversion to Christianity?

Surprised by Joy is C.S. Lewis’s autobiography describing his movement toward Christianity.

Published in 1955, the book traces Lewis’s intellectual and spiritual development from childhood through his return to Christian belief. The title refers to “joy,” Lewis’s term for a recurring feeling of intense longing or desire that he associated with experiences of beauty, literature, and imagination.

Lewis had become an atheist in his youth, but he gradually returned to belief in God during the 1920s. His conversion was influenced by conversations and friendships, including those with Owen Barfield and J.R.R. Tolkien. Lewis later described himself as having been converted to theism in 1930 and to Christianity in 1931.

Surprised by Joy is not the same as A Grief Observed, which records Lewis’s anguish after the death of his wife, Joy Davidman. Nor is it Mere Christianity, a work developed from wartime radio talks rather than a conventional autobiography.