Premise: Króka-Refs saga (   ) or the Saga of Ref ('Fox') the Sly is one of the Icelanders' sagas. Written in the 14th century the saga relates the adventures of Ref Steinsson, a "coal-biter" or "male Cinderella", whose unpromising origins lead him to greatness in both combat and subterfuge.
Hypothesis: The Saga of Ref the Sly is based on "Cinderella".