10 Doctor Who Moments You Didn't See Coming
2. The First Regeneration
There are many moments in the classic era that were probably quite surprising for fans at the time, from the true identity of The Watcher in Logopolis, to the Valeyard being alive at the end of The Ultimate Foe (we're still waiting for that one to be revisited, by the way).
But without question, the grandaddy of classic twists has to be the regeneration of First Doctor William Hartnell into Second Doctor Patrick Troughton, which, for many avid viewers of the show, was something of a shock cliffhanger.
Back in those days, regenerations were nowhere near as highly-publicised as they are today. In fact, as pointed out by The Guardian, some 1966 newspapers relegated the Troughton takeover news to a tiny paragraph at the bottom of a page.
Unlike today, the concept of recasting wasn't commonplace back then either, so we can only imagine how stunned the nation was when its favourite TV hero died, got a glowy face, and then changed into another dude.