Mapping Greyhawk on Blackmoor

The Greyhawk setting has a lot of fans - waaay more than Blackmoor.  But, in a way, that's an odd thing to say, because the city of  Greyhawk and the land of Blackmoor were birthed on the same continent at the dawn of the game.  

Of course, after Arneson and Gygax went their seperate ways, so did their campaigns.  Arneson continued to develop Blackmoor, which got transported first into the Wilderlands, and then into Mystara's ancient past, and then into an unspecified world. Each time Blackmoor moved, the setting built on it's own internal history, more or less, even though the outside world changed.

Meanwhile, The world of Greyhawk never lost it's Blackmoor, seemingly a vestigial of games past, largely neglected in play.

Blackmoor, as shown on maps of World of Greyhawk, is radically different from the map Arneson drew of his setting - but perhaps not entirely unrecognizable. Naturally there have been attempts to merge Arneson's vision of Blackmoor, with that neglect spot on the Greyhawk map.  Largely, these have involved redrawing the Greyhawk map - understandably not something very popular with Greyhawk fans.

The other day, a thought occured to me.  What if the differences found on the World of Greyhawk maps could be explained by an actual, world altering event?  After all, cataclysms are a familiar trope in Greyhawk, and indeed in D&D in general.  

Since Greyhawk has it's own lore regarding the current state of Blackmoor, any changes would have to have happened in the past - a past that could be greatly enriched with Blackmoor's deep well of gaming material.  Then what seemed the perfect solution hit me - the Egg of Coot.

The Egg of Coot exists in Greyhawk lore much as in Blackmoor, and has been hell bent on conquering the Blackmoor from the start.  In Blackmoor canon, The Egg launched 4, ultimately failed attempts, however, according to Greyhawk lore, The Egg eventually succeed. 

How is unspecified, but, let's suppose the Egg unleashed mighty magics to alter the face of the land, drain the bay that seperated it's forces from Blackmoor, flatten cities, alter the course of rivers and so on.  What then would the land look like?

Below are the maps to show this.  The first is a printout of the Zeitgeist games Blackmoor map with the "new" coastline drawn in black sharpie.  As a template, I used the version of Blackmoor shown in Dungeon #126 - primarily because it had a scale bar I could and did use to match scale to the Blackmoor map.  

Once I had the scales matched I layed one map atop the other and was delighted to find that the towns of Blackmoor and Maus/Mosshold lined up exactly - probably not a coincidence.  Then I just redrew the coastline following the Greyhawk exemplar.

Note that the coastline is a bit altered by me in the southern portion to account for major mountainous areas which I presume were less likely to flood (though one entire range- the Crystal Peaks - is now underwater).

Here is the Greyhawk map from  Dungeon #126 (2005) I used as a guide:

This map shows the location of major towns onto the Greyhawk map:

And to make it a bit clearer, here is a featureless map with the towns included:

You can see Blackmoor and Maus/Mosshold line up perfectly, as they should.  Glendower/Glendour are quite off, but that is the only significant location that doesn't match, so I would suggest  WoG placement of Glendour is simply a map error.

You might ask: What's the advantage for the Greyhawk player to add these Blackmoor details to their games?  The answer is the wealth of detail that can be mined from Blackmoor products.  Most of these locations will no doubt be abandoned ruins full of monsters and ancient treasure at the CY 590 period in Greyhawk.  Some may be embattled castles and lost enclaves of magic.  The possibilities here really abound.  Enjoy.