10 TV Shows Which Completely Changed Their Premise

9. Doctor Who

Doctor Who's premise is reinvention, but the classic series underwent a major retool which is still felt in the modern incarnation. It was originally intended as an educational series which would use time travel to teach children about history and science, so the First Doctor was accompanied by his young granddaughter Susan and her two schoolteachers.

The concept of regeneration wasn't even floated until it became apparent that William Hartnell's health was failing three years after his first appearance. The popularity of the Daleks and other science-fiction elements of the show led to a gradual shift away from these storylines and towards the sci-fi epic we recognise today.

Occasionally the Doctor still visits historical figures in the revival, but it's hard to argue that Ten's romance with Elizabeth I was intended to teach children about the Tudors.