Variant Known World
by Mark SI'm using a variant version of Mystara, and have messed around with Geography quite a bit. I wanted to make Thyatis a bigger empire on Brun, as well as having substantial overseas territories. I therefore made Karameikos and Minrothad explicitly semi-autonomous territories of the Empire. I moved Ylaruam to the Great Waste, south of Jahore, and used John Biles's idea of a Russian-style nation called Khoryv in its former place; this too is a dependency of the Empire (no link to hand, but it's on these boards somewhere, with a map). Thyatis now sits in the centre of substantial holdings on Brun, plus the Isle of Dawn, Pearl Islands and Ochalea.
Other geographical changes
*Ethengar moved to the Adri Varma Plateau and beyond -- a vaste open steppe for them to roam with horses.
*Former Ethengar territory taken up (mostly) by an expanded Broken Lands. Orcs are a major problem in my Mystara, and they lord it over the goblin races. They are the inheritors of Azcan culture (being former slaves of that empire); so I've changed names to more Nahuatl-sounding (Thar is now Tatlaca, etc.)
*There's some land to the west of Northern Reaches and north of Dengar which is not claimed by the orcs; I've put Irilian in here (a city described in ancient issues of White Dwarf magazine). This is a free city, powerful in size but much threatened by the orc hordes.
*Ostland now has some territory in Westrourke on the Isle of Dawn; it seemed too small without it.
I think that's all the geographical changes I've made; the tenor of some of the countries have changed as well to account for shifting loyalties given the geographical changes, along with some personal preferences. It took a lot for me to take the first step to change Mystara, because I loved the setting so much, but then once I started messing, I couldn't stop! I hope you will forgive my heresy.