Imirrhos: The Original Known World

In 2015, Lawrence Schick revealed the hidden origins of the B/X continental setting in "The 'Known World' D&D Setting: A Secret History" posted on "Black Gate: Adventures in Fantasy Literature".

Map of the original "Known World" setting, also known as the continent of Imirrhos (east and west portions originally posted separately, on Black Gate).

Schick collaborated with Tom Moldvay in the mid-1970s to create a fantasy world setting for their shared D&D campaign.  After Schick was hired by TSR in 1979, he was soon joined by Moldvay.

I can’t remember whether it was Moldvay or me who suggested it, but we proposed dusting off our Known World documents for use as the new, standard D&D campaign setting.  This got approved, I think by Mike Carr, and a revised version of our campaign map was hexed-up by the Art Department for use in X1, The Isle of Dread module, which was designed by Moldvay and Zeb Cook to be included in the Expert Set box.

Lawrence Schick, on Black Gate (February 7, 2015)

Within 24 hours of Schick's article, a colorized, annotated map of the "Original Known World" was posted by James Mishler, on "Adventures in Gaming v2" (February 8, 2015).  This was followed by a series of interviews with Schick (here, here, and here).

Photograph of the original wall map of the pre-TSR "Known World" on display in The Gamehole, as posted on Twitter (July 11, 2018).  (See also this tweet).

The original, full-color wall map created by Schick and Moldvay was restored and purchased by Alex Kammer of Gamehole Con in July, 2015.  (There are some differences between the black-and-white map and the full-color wall map.)

For many years, fans of the D&D Known World/Mystara setting theorized on possible connections between the Original Known World and Mystara.

A few months ago, Bill Wilkerson (a player and DM in the Original Known World campaign) graciously permitted a substantial number of pages to be scanned and uploaded to Google drive, accessible through links in "More OKW documents!" (January 20, 2022) on the Piazza.

First page of the handwritten "History of Imirrhos", describing the history and geopolitical entities of the Original Known World.

Of particular interest are notes on the "History of Imirrhos", which detail a cataclysm in which the southern third of the continent sank to become a series of archipelagos and islands, as well as short descriptions of the various regions.

Wilkerson's material involving the continent of Imirrhos is being actively studied by fans of the Known World/Mystara, with plenty of discussion on the Piazza and elsewhere regarding this lost OD&D setting (see also this post, over at Zenopus Archives).