Domesday Book (Original)

From wikipedia:

The Castle & Crusade Society was a chapter of the International Federation of Wargaming dedicated to medieval miniature wargaming.
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The C&CS published a newsletter called the Domesday Book. Its first issue is dated March 1, 1970; both the first and second issues are only a single page long; circulation of this newsletter would never exceed eighty copies.

The fifth issue contained a set of rules called the LGTSA Medieval Miniatures rules which would be expanded and published by Guidon Games as Chainmail in 1971; this being one of the primary predecessors of Dungeons & Dragons (Original Edition).

Issue #9 contained a map of the Great Kingdom, the campaign environment in which the cities of Blackmoor and Greyhawk were first initially developed for the purposes of a C&CS play-by-mail game.

Issue #13 of the Domesday Book published some early details, as well as a map, of Blackmoor from Dave Arneson's first fantasy role-playing campaign in July 1972. This article was reprinted almost verbatim in The First Fantasy Campaign, with slightly altered map art.