The Westerlands are the main setting of my Realmwalkers campaign because of Geoff's amazing map. But the more I fleshed out the world and it's history, the more world I realized I needed. Ironically there is land west of the Westerlands. It is this map.
It will be added into my homebrew later as an "expansion" of sorts. I know in the frozen north of the Westerlands there are barbarians and giants, the south is the jungle home of the Draken, the desert dwelling Grimalkin live in the southeast, and the Red Wastes in the east spawn Orcs and necromancers. But the primary humans of the Westerlands are the last remnants of the once great Atilaen seafaring people who moved inland when the oceans rose and drowned most of their culture. They have no idea that more of them survived and fled west across the waters. I just need to ponder it some more to figure out how different they are from their eastern cousins. Definitely something to think about.
The other issue is what to call it. The artist asked I not use the name he gave it, which is completely fair.
I think maybe I'll call it/them the Sunset Kingdoms. The largest island is the real seat of power, and each of the other islands is governed by a duke/count. They are constantly vying for more power and thus always in conflict. Their religion still worships the sea and some worship stones - this causes its own internal strife. When they come into contact with the sun worshipping, generally peaceful Westerlanders (I think they'll call them Dawners) war is practically inevitable. When some Westerlanders learn that there are people practicing the ancient religion of the sea, they too want to go back to their roots and leave, causing a rift within their own lands.