Howard Pyle was the first person in the modern era to collect all the Robin Hood ballads that had come down from the midieval era and put them into a modern format, structured as stories and so forth. Essentially every version of Robin Hood in the past century has drawn on Howard Pyle's Robin Hood as its major source, and reading this book is the best way to understand why the minor characters in (for example) Kevin Costner's "Robin Hood, Prince of Thieves" are named things like "Will Scarlet" or "Much the Miller's Son."