Geoffrey said:
The hard work you put into it shows, Mr. Gygax. Aerth is my favorite generic FRPG world out of all the multitude published. In the forward to the original Necropolis, Lester Smith (I think) mentioned that Aerth has its roots in your unpublished world of Oerth (with the published Oerth being a very different version). Can you expand on that?
Thanks, Geoffrey
It was Les who put that into the forward, and yes, I can expand on it a bit.
When I initiated the Greyhawk campaign, I envisaged a world of parallel earth sort. Thus the geography then assumed was pretty close to that of earth. Being busy running game sessions, creating dungeon levels, the map of Greyhawk City, writing new material, and also really enjoying "winging it," I never did a large-scale map for the world.
When IU was asked to create a campaign setting for TSR to market, I did a new and compact "world"--that only in part, of course, as that was all I could fit onto the two maps allowed. So that became the World og Greyhawk.
At that point my campaign play gradually moved from the amorphous "real" planet on which Greyhawk was located to the material one published by TSR. Being busy as ever, saving what amounted to duplicate labor was happily accepted.
After the split with TSR, I returned to my original concept, painted over a globe of the earth to match my original ideas for a fantasy alternate earth, and thus Aerth was born. My wife and some others thought I'd lost it when they saw me with acrylics and brushes altering the globe

I still have it around somewhere...
Only after I had the fullly done globe of Aerth did I then set about the research needed to quantify all that was thereon.
Ciao,
Gary