D&D historians may be interested in this fascinating article by TSR's head of design and development in the 1980s, Lawrence Schick. It deals with the creation of the Known World (which later became Mystara), one of the earliest D&D campaign settings (first officially mentioned in Module X1: The Isle of Dread). "We decided to plot out a single giant Pangea-type continent on which there would be fantasy-fictionalized versions of each of the above cultures. We also added homelands for the nonhuman races: Orcs, Goblins, Elves, Dwarves, Hobbits, Lizard-Men, Deep Ones, Kzinti Catfolk, and Barsoomian Tharks, as well as a pirate kingdom, and areas where prehistoric creatures were the norm. Plus in every land there would be hidden cults that worshiped Lovecraftian Elder Gods... We dubbed this setting the “Known World,” to imply there was more out there yet to be discovered..."
The article is well worth a read if D&D history is even slightly your thing.
The article is well worth a read if D&D history is even slightly your thing.