The Sargauth Enclave in present-day Undermountain is partially destroyed as a result of Karsus's Folly, and the Netherese arcanists that survive are twisted into magically potent undead that will become known as the Skulls of Skullport. These Skulls find that they are now part of the mantle that they were working on, and now cannot travel beyond it's borders. »
The necromancer Shradin Mulophor takes up residence in the ruins of Sargauth Enclave (after asking permission from Halaster Blackcloak and also becoming his apprentice), establishing a small trading settlement that will soon becomes known as Skullport, Port of Shadows. The Lord of Bones, as Shradin comes to be known, encourages trade with other Underdark powers by linking the River Sargauth with subterranean waterways and creating portals leading to distant seas. »