Part One- DOCtrine, cannon whatever you choose to call it, Numbero Uno, The First
William Hartnell was the first. When he decided to leave the show for health reason the BBC had to make a decision cancel the show or continue on. They didn’t want to cancel the show and they didn’t want to cover it up like the American stations did on Bewitched(look it up) Footage is rare except that of the actual regeneration, although at the time it was called a renewal. Unfortunately most of the episode Tenth planet is missing. I can’t say how Harntnell acted out his last lines, or how Pat Troughton went about establishing his person and quirks. This regeneration also sets up the tone for how all future regenerations are experienced. If it had failed, we would not be talking about a man in a blue box today. This is the only pre/post regeneration sequence I have not PERSONALLY seen, excluding the clips that remain. The transcripts I believe are available due to zealous fans who recorded the audio for TV shows so they could “watch them again and again.( Go, right now, kiss your DVR! Then kiss wherever magic device you use to surf the web. It is thanks to them, and people who imagine bright futures watching shows like Star Trek and Doctor Who, no other TV show will ever have this problem again.) There have been rumors floating around for years that these tapes actually exist. If they were mine I would make sure the world could have them. That being said maybe they are holding them for the 50th.