Historically...

You've got to be kidding? :) Prince and the Pauper is a satire written by Mark Twain and is not meant to be historically accurate. It's just good fun. You want accuracy go for Anne of a Thousand Days or the Six Wives of Henry VIII.

The portrayal of Elizabeth was more great fun. :)

It this fascinating concept called a "story", a work of fiction.
Try Googling "story" for more information.