Since its debut in the early 1960s, Doctor Who has entertained, enthralled, and enraged its fanbase in equal measure, remaining a fixture of British culture for six straight decades (if you forget about the time it got cancelled).
Such a broad history comes with a multitude of facts, figures, and statistics to memorise - and bore people with at parties! Whovians are among the most knowledgeable and passionate fans in the world, but there are some surprises on this list that might shock even them.
The world of Doctor Who is far broader than what you see on TV. Like any drama, some of the juiciest stuff takes place behind the cameras, and it's those secrets that will make you view the show in a very different light.
From production snafus, to potential castings, to the inspiration for classic characters and props, this list doesn't contain all of the show's secrets, but it will whet your whistle, and may just encourage you to do some more digging.
The Whoniverse is a big place, and there's a lot to find out there.
10. The Twin Pilots
Doctor Who kicked off on 23 November 1963, with the show's first episode, An Unearthly Child.
In this adventure, we meet the Doctor (played by William Hartnell) for the first time. He's parked the TARDIS in a scrapyard in England, kept company by his granddaughter Susan. Don't ask why the Doctor has a grandchild, it's far too complex to get into right now.
As pilot episodes go, An Unearthly Child did the job just fine. It introduced the characters, the premise, and the rules of the universe perfectly well, but did you know that two versions of the episode exist?
The first version of An Unearthly Child was deemed not good enough by the show's creator, Sydney Newman. He didn't like the way the Doctor was dressed, or how mean he was to his granddaughter. As a result, huge chunks of it were re-filmed and a second version was put together, with the first version not being publicly released until 1991.
Suppose we shouldn't be shocked that a show about regeneration went through a few different incarnations before broadcast!