A new season of Doctor Who premieres this Saturday, August 23rd, starring a brand new, somewhat older Doctor (Peter Capaldi). The show has been around for more than 50 years and 800 episodes, but while that may seem daunting, surprisingly little of that matters. He's an alien — specifically a Time Lord — with a time machine that's bigger on the inside and looks like a police box to the naked eye. He has a Sonic Screwdriver for fixing plot holes and a companion to serve as character foil.
More importantly, The Doctor regenerates, which is to say he can "die" and be replaced with a new actor without screwing up the canon. Here's a look back at the (more than) 12 Doctors and their goodbyes.