Cinderella was a fairy tale.
A Lapino, a species that fed on emotion, crashed on a planet. When the TARDIS landed on the planet, it was going to kill Vicki or Steven Taylor to generate enough emotion to power a rescue message. The First Doctor convinced it that there were other options, so they put on a dramatic presentation of Cinderella to more positive emotions on which to feed. (PROSE: Planet of the Bunnoids)
Behind the scenes Edit
Lily James, who portrayed Cinderella in Disney's 2015 live-action adaptation of the story, has been in a relationship with Eleventh Doctor actor Matt Smith since 2014. Incidentally, it was the Eleventh Doctor who appeared opposite Cinderella in the Time Lord Fairy Tales short story, Cinderella and the Magic Box.
The aforementioned film also featured Derek Jacobi.