Trying to find information on the timelines of Halaster Blackcloak and his apprentice Trobriand. It seems that the Seven constructed the Hold in 168DR. Halaster takes complete control of the Undermountain in 309DR. The events of the Dungeon in the Mad Mage takes place The events of the Dungeon in the Mad Mage takes place over 1000 years later. For the rest of the surviving Seven, they have canonical reasons to still be alive, but Trobriand is still just a human. How has he stayed alive for 1200+ years or was he not part of the original Seven?
— Nupperibo (@Justincred1ble_) June 18, 2019
The increasingly-rare Potions of Longevity were something many Imaskari archwizards could make, or knew the spells behind, and so could make use of themselves. The ranks of these mages included Halaster and his apprentice Trobriand.#Realmslore
— Ed Greenwood (@TheEdVerse) June 18, 2019
But potions of longevity cap out at a max possible 120-year age reduction… Nope. Only those latecomer potions that were crafted during a particular game edition. ;}
In-Realms lore (that's "happened" already) trumps later metagaming nerfing; the later rules changes don't undo what's befallen in the world, just govern what happens henceforth (unless…— Ed Greenwood (@TheEdVerse) July 11, 2019
…revealing new information that leads to a new understanding of past events (i.e. the earlier chroniclers got it wrong, in light of the limits of their knowledge). In this case, Potions of Longevity vary greatly depending on who crafted them and how (the "secret formula," if…
— Ed Greenwood (@TheEdVerse) July 11, 2019
…you will). The 120-year-limit applies to the most widespread ("standard") version of the potion, now most widely found in treasure hoards and the like. (That is, the version of which most were made, and so are most "popular" in the Realms.)
— Ed Greenwood (@TheEdVerse) July 11, 2019
There's also a trick involving combining a potion of longevity and Phezult's Sleep of the Ages, but it's so dangerous I'll leave PCs to discover it for themselves.#Realmslore
— Ed Greenwood (@TheEdVerse) July 11, 2019
Is this what happened to Durnan and Mirt? Mirt was trapped in stasis in a blueflame item (see my Sage of Shadowdale trilogy) for over a century. Durnan's longevity is partly NDA, but when he retired from adventuring to run the Portal, he was sitting on a STACK of Potions of Longevity.#Realsmlore
— Ed Greenwood (@TheEdVerse) July 12, 2019