The story describes the encounters between Farmer Giles and a wily dragon named Chrysophylax, and how Giles manages to use these to rise from humble beginnings to rival the king of the land. It is cheerfully anachronistic and light-hearted, set in a fantasy Great Britain of long ago, with mythical creatures, medieval knights, and primitive firearms. It is only tangentially connected with the author's Middle-earth legendarium: both were originally intended as essays in "English mythology".