There's a short write-up on the official Neverwinter website that shares some background information about the pirate captain Traven Blackdagger and the crumbled ruins that remain of his former stronghold, Blackdagger Keep. Here's a sampling:
Traven Blackdagger was a pirate captain who terrorized the Sword Coast between Neverwinter and Luskan in the years after the Spellplague. He had gathered a formidable force in his seaside keep and proclaimed himself lord of the lands around it, threatening death to any who opposed him. But when Mount Hotenow erupted, the cataclysm toppled his keep to ruins. Traven and his brother Malus died, buried in the rubble along with all of their ill-gotten treasure.
The ruins of Blackdagger Keep lay forgotten for decades until recently when it was found by bandits and claimed as their hideout. Unbeknownst to them, another power was already at work in the dungeons beneath the keep. A Thayan Red Wizard named Kallos Tam discovered the ruins months earlier and was searching for lost magical items. When Kallos saws the bandits, he saw an opportunity to consolidate a power base for the Thayans.