Dragonspear Castle

Dragonspear Castle was a fortress, built across three low hills on the southwestern edge of the High Moor, east of Trollbark Forest and just north of where the Coast Way joins the Trade Way. Extensive tunnels were dug under the keep, connecting with an underground river, the already-abandoned city of Kanaglym, and hence the larger Underdark. The Castle became most notable for its interplanar portals, through which come baatezu and other fiends.

History
The castle was built in 1255 DR by the half-dwarf Daeros Dragonspear, around the lair of his ally Halatathlaer. Ithtaerus Casalia set in motion the destruction of the Castle by creating a portal in 1290, and following the exodus of its defenders it was taken over by various tribes of humanoids, notably hobgoblins. In 1315, armies from Waterdeep and Baldur's Gate cleared out the ruin and built a temple of Tempus. One or more hostile entities including the Zhentarim opened new portals, and by 1354 the castle was controlled by devils. The next years were spent fighting off fiends and the humanoid armies they gathered. In the 15th century, the ruins are claimed by Born and a growing army of undead.


 * 1255 DR: Daeros Dragonspear emerges from Kanaglym, bearing a fortune in gems. He builds Dragonspear Castle around the lair of Halatathlaer.


 * 1290 DR: Ithtaerus Casalia creates the first portal to Avernus in Dragonspear Castle, binds Halatathlaer, tricks Daeros Dragonspear into entering the portal (and effectively killing himself), and lures other dragons to the castle with vision of a free dragon hoard. Three hopeful dragons arrive and battle each other, slaying Halatathlaer and demolishing most of the fortress.  The surviving dragon, Sharndrel, is incensed by the deception and slays Ithtaerus.   The ruins are soon claimed by bandits and humanoids.


 * 1305 DR: Hobgoblins seize Dragonspear Castle and raid the Trade Way and surrounding lands.


 * 1315 DR: Armed expeditions from Waterdeep and Baldur's Gate finally sweep through Dragonspear Castle. Unable to destroy the portal they establish the Hold of Battle Lions, a fortified temple of Tempus.


 * 1354 DR: Devils take Dragonspear Castle, arriving through new portals.


 * 1356 DR: The Dragonspear War. A strange mist cloaks the ruins of Dragonspear Castle, said to resist even the dispelling efforts of Khelben.  The forces of Waterdeep and Baldur's Gate once more converge on Dragonspear Castle, setting fire to the structures there and defeating the devils.


 * 1363 DR: The Second Dragonspear War. Devils retake Dragonspear Castle and build an army of humanoids, plus a dominated dragon.  This fiend-led army destroys The Way Inn and attacks Daggerford before being defeated by a motley force led by adventurers.


 * 1479 DR: The persistent mists remain. The castle is now controlled by undead led by Born.