Which medieval allegory inspired the title of C.S. Lewis’s book The Pilgrim’s Regress?

The medieval-style allegory that inspired the title of C.S. Lewis’s The Pilgrim’s Regress is The Pilgrim’s Progress. John Bunyan’s famous Christian allegory was first published in 1678 and follows Christian’s journey from the City of Destruction toward the Celestial City.

Lewis’s own book, published in 1933, presents a modern allegorical journey through competing philosophies and forms of belief. Its title deliberately signals a relationship to Bunyan’s work while reversing the direction of the journey. Lewis’s protagonist moves backward through intellectual positions before rediscovering Christianity.

The title is sometimes confused with Edmund Spenser’s The Faerie Queene or William Langland’s Piers Plowman, both important English works with allegorical elements. However, Lewis explicitly modeled his title on Bunyan’s book. The Pilgrim’s Regress was Lewis’s first published book after his conversion to Christianity and was initially published under the name C.S. Lewis.