:For an alternative, likely accurate origin, read the story of Samuel Foote, proprieter of now the Theatre Royal. In the book, London's Strangest Tales, and referenced around the Internet, the following story is told - the following is not the best version told, but it was easiest from a copy/paste perspective! (from the Theatre Royal Haymarket website):  

 "1754 saw a change of administration for the Hay Market, as the flamboyant Samuel Foote, a celebrated mimic, stepped into John Potter’s shoes. Foote’s name was to become somewhat ironic as, handed a rather frisky horse at a Royal Hunting Party as a prank, Foote was thrown from his steed, breaking his leg severely and requiring amputation. 
 Although he feared his career was over, the Hay Market was to benefit strangely from his misfortune. Horrified that the joke had so misfired, the Duke of York, a close personal friend and fellow guest at the hunt, asked if anything could be done for Foote. Immediately, Foote replied that all he wanted from life was a Royal Warrant and Patent for his ‘Little Theatre in the Hay’." 

 Apologies for the bad formatting/attribution, but I'm not a Wikipedia Specialist ~Edd