So, the Discworld made its first appearance in The Colour of Magic, right? Well, yes and no. You see, two years before The Colour of Magic there was Strata!
Strata tells the story of Kin Arad, a 210-year-old terraformer who thinks she knows the history of the universe. You see, mankind is just the latest in a string of races who have shaped their universe to their own ends, creating planets with artificial histories of evolution built right into the strata of their rocks, a history as artificial as the worlds themselves. But, when an ancient astronaut steers her and two companions to a flat, disc-shaped world, an impossible world full of mysteries, Kin decides that she must get to the bottom of it all. This is the story of the discworld, and the history of...everything.
Now this is one of only two purely science fiction novels that Terry Pratchett ever wrote (the other being The Dark Side of the Sun). But, while perhaps just a little bit more serious than your typical Discworld book, it is still quite fun and entertaining. As you would expect with Pterry, the characters are quite interesting and the storyline always seems to keep you off-balance. I really enjoyed this book, and highly recommend it to anyone who likes a good story.
If it's not exactly the father of the Discworld stories, it is at least the god-father of them. So, do yourself a treat and check out Strata!