Which Tolkien essay was first delivered as a 1939 lecture about fantasy and fairy stories?

On Fairy-Stories was Tolkien’s 1939 lecture and essay about fantasy and fairy stories.

Tolkien delivered the talk as the Andrew Lang lecture at the University of St Andrews on 8 March 1939. He argued that fairy stories should not be dismissed as material only for children and examined how they can offer recovery, escape, and consolation.

The essay is especially associated with Tolkien’s idea of eucatastrophe, a sudden joyful turn in a story. He described it as the “sudden joyous turn” that produces a profound emotional effect, while distinguishing it from a simplistic promise that every story must end happily.

On Fairy-Stories was later published in expanded form. It appeared in the 1947 collection Essays Presented to Charles Williams and was also included in Tree and Leaf, alongside the short story Leaf by Niggle. It is an important statement of Tolkien’s literary ideas, not a narrative from Middle-earth.