To sum up from the previous link and adding a few of my own comments:
1972 - D. Arneson begins his Blackmoor campaign using altered rules for 1:1 Chainmail and its Fantasy Supplement. Arneson and G. Gygax collaborate and G. Gygax begins his Greyhawk campaign shortly thereafter.
1974 - D&D first receives wide release.
1975 - Greyhawk and Blackmoor Supplements published, with very little campaign material, although Blackmoor Supplement has first published version of the Temple of the Frog, a famous scenario set in Blackmoor.
1976 - Judges Guild begins publishing products for its City State/Wilderlands campaign
1977 - Judges Guild publishes the First Fantasy Campaign by D. Arneson, which ties Blackmoor into the Wilderlands campaign.
1980 - Greyhawk Folio published, which contains a reference to Blackmoor in the northwest and the City of the Gods. This is not D.A.'s Blackmoor, but rather a tribute to it.
1981 - The Known World is introduced in the Cook edited Expert box set and X1 Isle of Dread.
1986 - DA1 Adventures in Blackmoor is published, which ties Blackmoor into the distant past of the Known World. DA2 Temple of the Frog, DA3 City of the Gods, and DA4 Duchy of Ten follow.
1990 - Hollow World box set details much history and takes some elements from Blackmoor - specifically the technology obsessed Blackmoor Elves. Many other Known World/Mystara/Hollow World products feature ancient Blackmoorian artifacts and elements of its history. In some ways the cataclysm that destroyed Blackmoor is the defining moment in the world's history.
200? - Publication of a 3e Blackmoor.
The only items that can probably be considered "canon" Blackmoor, is the Temple of the Frog scenario from the Blackmoor Supplement, the First Fantasy Campaign, and the non-Known World elements of DA1, DA2, and DA3. All others are works by persons other than Dave Arneson and will probably not be taken into account at all for the 3e Blackmoor.
R.A.
Updating RA's Publication Timeline for Blackmoor:
1972 - D. Arneson begins his Blackmoor campaign using altered rules for 1:1 Chainmail and its Fantasy Supplement. Arneson and G. Gygax collaborate and G. Gygax begins his Greyhawk campaign shortly thereafter.
1974 - D&D first receives wide release.
1975 - Greyhawk and Blackmoor Supplements published, with very little campaign material, although Blackmoor Supplement has first published version of the Temple of the Frog, a famous scenario set in Blackmoor.
1976 - Judges Guild begins publishing products for its City State/Wilderlands campaign
1977 - Judges Guild publishes the First Fantasy Campaign by D. Arneson, which ties Blackmoor into the Wilderlands campaign.
1980 - Greyhawk Folio published, which contains a reference to Blackmoor in the northwest and the City of the Gods. This is not D.A.'s Blackmoor, but rather a tribute to it.
1981 - The Known World is introduced in the Cook edited Expert box set and X1 Isle of Dread.
1986 - DA1 Adventures in Blackmoor is published, which ties Blackmoor into the distant past of the Known World. DA2 Temple of the Frog, DA3 City of the Gods, and DA4 Duchy of Ten follow.
1990 - Hollow World box set details much history and takes some elements from Blackmoor - specifically the technology obsessed Blackmoor Elves. Many other Known World/Mystara/Hollow World products feature ancient Blackmoorian artifacts and elements of its history. In some ways the cataclysm that destroyed Blackmoor is the defining moment in the world's history.
2004-2008 - Publication of a 3e Blackmoor.
2009 - Dave Arneson passes away. Blackmoor the First Campaign (4E) published.
2010 - Blackmoor lisence ends.
Havard