The Undermountain

More than one thousand years ago, the wizard Halaster Blackcloak journeyed from a distant land to the base of Mount Waterdeep, perhaps acceding to the whispered summons of providence. Some believe he hailed from the nearly forgotten empire known as the Cradlelands. In ages past, humanity spread from the Cradlelands across Faerûn, originating from what is now the Plains of Purple Dust, a wasteland birthed out of a conflict with the gods. Others give Halaster less ancient origins, placing him among the early wizards of Netheril, or asserting that he came from a southern nation long since buried by sand and time. Whatever his origin, scholars have recorded that Halaster brought with him seven apprentices to Mount Waterdeep. With the Seven guarding his back, Halaster tapped into his immense power to summon beings from other planes of existence to help him build a wizard’s tower to dwarf all other wizard’s towers. But as the seasons wore on, the Seven saw less and less of their enigmatic master. Halaster continued to use fell creatures from distant planes for tunneling and other construction beneath his tower, and the wizard kept the nature of most of his underground dealings a secret from the Seven. Eventually, Halaster’s exploration broke into the Underhalls, a complex of tunnels and rooms built by the dwarves around a mithral mine beneath Mount Waterdeep. The architects of the Underhalls, the Melairkyn clan, had long ago been killed or dispersed, and warring duergar and drow had settled in the ruins. Halaster began a crusade against both the drow and the duergar, participating in wild hunts with extraplanar allies through the tunnels. The stubborn duergar dug in until the mithral was largely mined out; then they abandoned the Underhalls, leaving the drow to fight Halaster and his minions alone. The Mad Mage rounded up the remaining dark elves, trapping some of their souls for use in his dark magic, while twisting the bodies and enslaving the minds of others. Once he had wrung the drow of their usefulness, Halaster Blackcloak tunneled on, ever downward, indulging his inexplicable compulsion for delving deeper and deeper into the mountain.

Using his underground complex as a base of operations, Halaster traveled to other planes and distant lands, collecting strange and dangerous creatures to live as prisoners, servants, or guardians in Undermountain. Populating and defending the dungeon became an obsession. Over time, the mage’s preoccupation with Undermountain electrified his eccentricities and infused him with an air of unconcealable madness.

Halaster’s apprentices came and went. Some left only to return — inexplicably drawn down into Undermountain’s depths. Others remained by his side. As they began dedicating more attention to their private obsessions, madness settled into their souls as well.

During the years Halaster quested on other planes and sequestered himself in his tunnels, his magnificent tower and its surrounding walls fell into ruin. In time, the city now known as Waterdeep developed in the shadow of Mount Waterdeep and spread down to the harbor. As the city sprawled outward over the years, it came to surround the ruins of Halaster’s home. Undermountain was known to those early settlers, and they often sent criminals into its endless depths as punishment. So it was for many years, until an intrepid adventurer named Durnan delved into the labyrinth beneath the tower and returned alive, laden with riches and countless harrowing tales. Durnan used his new fortune to demolish the remnants of Halaster’s tower and built an inn over the well he had used to descend into Undermountain, and call it The Yawning Portal. Durnan owns and operates the inn and tavern to this day, serving patrons and inviting the brave and foolish alike to test their mettle in the Dungeon of the Mad Mage.