So, the Quest of the Dungeons and Dragons continues, with a little help from the White Dwarf.
No firm date yet for the start of the campaign, but I've been trying to reconcile various things, including the three two-part scenarios from WD that I have: WD49-50's 'The Key of Tirandor' (the first issues of WD I bought, back in 1984 I think); WD56-57's 'The Sunfire's Heart' (with its sketchy history of the Solarian Empire going back 1700 years); and W80-81's 'Ancient and Modern' (with its setting in Theem'hdra going back thousands of years).
So... the narrative we are given of Tirandor (its fall 1000+ years ago and the end of Magelords) is not quite all. Mylakhrion, the Theem'hdran sage, was also a Mage of Tirandor, one of very few to escape its fall, 1700 years before the time of the PCs. Following the Fall of Tirandor (which co-incides with the destruction of the City of Ell/Pii from the Theem'hdra setting), the Solarian Empire is founded - to then collapse itself a little more than 500 years ago.
Kluhn, the city of Teh Atht in 'Ancient and Modern', more or less corresponds in this rationale to Brontir, the city where the action begins in 'The Key of Tirandor'.
All of this is piled onto the bones of the Mystara setting that I have from back when I got the Expert Set one Christmas in the 1980s. None of the Gazetteers - just the basic info in the Expert Rulebook and X1, the Isle of Dread. Instead of Shem and Yhemnis, that corner of the continent is covered by the Empire of Thyatis (one of the successors to the Solarian Empire, which is fitting as the description of the Empire is that it is similar to the Byzantine Empire, the eastern successor to the Roman Empire). Humquass in the Theem'hdra setting becomes Cynedacia, the site of the Lost City (B4) and home to King Alexander, who becomes a monarch of the Solarian Empire, and a successor of King Morgath who features in the tale about the Usurpation of Exior K'mool. B4 is set in Ylaruam, another state founded on the break-up of the Solarian Empire, by a local governer-turned-emperor, in much the same way as Alexander the Great's Empire fractured after his death.
This is neither the 'official' Mystara, nor the canonical Theem'hdra. And only the barest bones of Tirandor are left. The connection to the Solarian Empire is a bit stronger, but that polity is in the scenario an imperial archipelago; in this campaign it is a substantially continental empire with some relatively unimportant island territories - corresponding to the islands of the Empire of Thyatis and the Minrothad Guilds.
There are other tie-ins. Along with the first part of 'The Sunfire's Heart' (which requires scanning and re-printing as its text is substantially black-on-purple and murder to read), WD56 also features a short article on using the setting of 'The Belgariad' for D&D games. I'm using as much as I can of course. Not the map, obviously, but the serpent-animated Mud Men, Algroths (mountain-dwelling troll-yetis), Belgarath the Sorcerer (another Tirandorian Mage, or perhaps a little more likely, like Teh Atht a thoroughly modern mage who has studied all he can of the arts of Lost Tirandor?) and the evil god Torak. Also included are two scenario outlines, one concerning a mountain expedition to find a powerful magical artefact, and the other to do with the secretive Ulgos, a mountain-dwelling race of albino separatists. Hmm, perhaps the lost Marags, and almost-lost Ulgos, of the Belgariad are beginning to sound a little like the Anaks of the mountains of Tirandor... perhaps not all of them are lost? The rest inhabit the mountains where Rockhome now is in Mystara, which once upon a time was the location of Tirandor.
Of course, how this could work if the lads decide they want the campaign to be set in Middle Earth, I'm not so sure. Perhaps the Solarian Empire could become Gondor, but it might be a little difficult to shoe-horn Tirandor into the history of the Third Age. Somewhere in the White Mountains, perhaps? It might be just about possible...