We like to think that we invented everything, and more-or-less recently, but the fact of the matter is that there are no new ideas. Everything we think is nifty is either a rip-off, spin-off or direct product of something that came before. And the shared universes we’re seeing nowadays - like the Marvel Cinematic Universe, the DC Extended Universe, the Arrowverse and beyond - are no exception.

Sure, those examples all sprang from shared universe comic books, but the idea of connected worlds isn’t even all that novel on television. The TV medium has been a hotbed of crossovers, interconnected storylines and franchise mentalities for decades. Some of these shared universes are very official, some of them are implied and some of them are exceptionally weird. But they all make the history of TV a fascinating subject, filled with fan theories, continuity errors and awesome revelations. Let’s take a look at 16 of the greatest, weirdest and - in one case - mind-blowingest shared TV universes on record!

16 Shared Universes From Before There Were Shared Universes 17 IMAGES

What are some of your favorite shared universes from the small screen? Let’s discuss it in the comments!